Complement

In grammar, a complement is a word, phrase or clause that is necessary to complete the meaning of a given expression. Complements are often also arguments (expressions that help complete the meaning of a predicate.

There are indicative as well as non-indicative complements in languages. Non-indicative complements follow the appropriate complementizers. Indicative complements do not follow complementizers but instead are included with special markers and clauses.

In many non-theoretical grammars, the terms subject complement and object complement are employed to denote the predicative expressions that serve to assign a property to a subject or an object:

• Ryan is upset. – Predicative adjective as subject complement
• Rachelle is the boss. – Predicative nominal as subject complement
• That made Michael lazy. – Predicative adjective as object complement
• We call Rachelle the boss. – Predicative nominal as object complement

The Cambridge Grammar of the English Language assigns the term "predicative complement" to both uses and shifts the terminological distinction to the verb:

• Ed seemed quite competent: — complex-intransitive verb + predicative complement
• She considered Ed quite competent : — complex-transitive verb + predicative complement

In many modern grammars, the object argument of a verbal predicate is called a complement. In fact, this use of the term is the one that currently dominates in linguistics. A main aspect of this understanding of complements is that the subject is usually not a complement of the predicate:

• He *wiped the counter*. – the counter is the object complement of the verb wiped.
• She *scoured the tub*. – the tub is the object complement of the verb scoured.

Infinitive

Regarding English, the term infinitive is traditionally applied to the unmarked form of the verb when it forms a non-finite verb, whether or not introduced by the particle to.

Hence sit and to sit, as used in the following sentences, would each be considered an infinitive:

• I can sit here all day.
• I want to sit on the other chair.

The form without to is called the bare infinitive; the form introduced by to is called the full infinitive or to-infinitive.

The other non-finite verb forms in English are the gerund or present participle (the -ing form), and the past participle – these are not considered infinitives.

Moreover, the unmarked form of the verb is not considered an infinitive when it is forms a finite verb: like a present indicative ("I sit every day"), subjunctive ("I suggest that he sit"), or imperative ("Sit down!"). (For some irregular verbs the form of the infinitive coincides additionally with that of the past tense and/or past participle, like in the case of put.)

Certain auxiliary verbs are defective in that they do not have infinitives (or any other non-finite forms).

This applies to the modal verbs (can, must, etc.), as well as certain related auxiliaries like the had of had better and the used of used to. (Periphrases can be employed instead in some cases, like (to) be able to for can, and (to) have to for must.) It also applies to the auxiliary do, like used in questions, negatives and emphasis like described under do-support. Infinitives are negated by simply preceding them with not.

Of course the verb do when forming a main verb can appear in the infinitive. However, the auxiliary verbs have (used to form the perfect) and be (used to form the passive voice and continuous aspect) both commonly appear in the infinitive: "I should have finished by now"; "It's thought to have been a burial site"; "Let him be released"; "I hope to be working tomorrow."

Perfect Infinitive

There are nonfinite constructions that are marked for perfect, progressive or perfect progressive aspect, using the infinitives, participles or gerunds of the appropriate auxiliaries. The meanings are as would be expected for the respective aspects: perfect for prior occurrence, progressive for ongoing occurrence at a particular time. (Passive voice can also be marked in nonfinite constructions – with infinitives, gerunds and present participles – in the expected way: (to) be eaten, being eaten, having been eaten, etc.)

Examples of nonfinite constructions marked for the various aspects are given below.

Bare infinitive:

• You should have left earlier. (perfect infinitive; for similar constructions and their meanings see modal verbs)
• She might be revising. (progressive; refers to an ongoing action at this moment)
• He must have been working hard. (perfect progressive; i.e. I assume he has been working hard)

To-infinitive:

• He is said to have resigned. (perfect infinitive)
• I expect to be sitting here this time tomorrow. (progressive)
• He claims to have been working here for ten weeks. (perfect progressive)

Present participle:

• Having written the letter, she went to bed. (perfect)
• The man having left, we began to talk. (perfect, in a nominative absolute construction)
• Having been standing for several hours, they were beginning to feel tired. (perfect progressive)

Past participle:

• We have been waiting a long time. (progressive, used only as part of a perfect progressive construction)

Gerund:

• My having caught the spider impressed the others. (perfect)
• We are not proud of having been drinking all night. (perfect progressive)

Other aspectual, temporal and modal information can be marked on nonfinite verbs using periphrastic constructions. For example, a "future infinitive" can be constructed using forms such as (to) be going to eat or (to) be about to eat.

Object

Traditional grammar defines the object in a sentence as the entity that is acted upon by the subject. There is thus a primary distinction between subjects and objects that is understood in terms of the action expressed by the verb, e.g. Tom studies grammar—Tom is the subject and grammar is the object. Traditional theories of sentence structure divide the simple sentence into a subject and a predicate, whereby the object is taken to be part of the predicate. Many modern theories of grammar (e.g. dependency grammars), in contrast, take the object to be a verb argument like the subject, the difference between them being mainly just their prominence; the subject is ranked higher than the object and is thus more prominent.

The main verb in a clause determines whether and what objects are present. Transitive verbs require the presence of an object, whereas intransitive verbs block the appearance of an object. The term complement overlaps in meaning with object: all objects are complements, but not vice versa. The objects that verbs do and do not take is explored in detail in valency theory.

Types

Various object types are commonly acknowledged: direct, indirect, and prepositional. These object types are illustrated in the following table:

The descriptions "entity acted upon" and "entity indirectly affected by the action" are merely loose orientation points. Beyond basic examples such as those provided in the table, these orientation points are not much helpful when the goal is to determine whether a given object should be viewed as direct or indirect. One rule of thumb for English, however, is that an indirect object is not present unless a direct object is also present. A prepositional object is one that is introduced by a preposition. Despite the difficulties with the traditional nomenclature, the terms direct object and indirect object are widespread.

The term oblique object is also employed at times, although what exactly is meant varies from author to author. Some understand it to be an umbrella term denoting all objects (direct, indirect, and prepositional), whereas others use the term to denote just a prepositional object.

Syntactic Category

While the typical object is a pronoun, noun, or noun phrase, objects can also appear as other syntactic categories, as illustrated in the following table:

Identification

A number of criteria can be employed for identifying objects, e.g: The object follows the subject. Languages vary significantly with respect to these criteria. The first criterion identifies objects reliably most of the time in English, e.g.

Fred gave me a book.

• a. A book was given (to) me. — Passive sentence identifies a book as an object in the starting sentence.
• b. I was given a book. — Passive sentence identifies me as an object in the starting sentence.

The second criterion is also a reliable criterion for isolating languages such as English, since the relatively strict word order of English usually positions the object after the verb(s) in declarative sentences.

The third criterion is less applicable to English, though, since English lacks morphological case, exceptions being the personal pronouns (I/me, we/us, he/him, she/her, they/them).

Verb Classes

Verbs can be classified according to the number and/or type of objects that they do or do not take. The following table provides an overview of some of the various verb classes:

Ergative and object-deletion verbs can be transitive or intransitive, as indicated in the following table:

The distinction drawn here between ergative and object-deletion verbs is based on the role of the subject. The object of a transitive ergative verb is the subject of the corresponding intransitive ergative verb. With object-deletion verbs, in contrast, the subject is consistent regardless of whether an object is or is not present.

Pronoun

Pronouns are a relatively small, closed class of words that function in the place of nouns or noun phrases. They include personal pronouns, demonstrative pronouns, relative pronouns, interrogative pronouns, and some others, mainly indefinite pronouns.

Personal

The personal pronouns of modern standard English, and the corresponding possessive forms, are as follows:

The second-person forms such as you are used with both singular and plural reference. You can also be used as an indefinite pronoun, referring to a person in general compared to the more formal alternative, one) (reflexive oneself, possessive one's).

The third-person singular forms are differentiated according to the sex of the referent. For example, she is used to refer to a female person, sometimes a female animal, and sometimes an object to which female characteristics are attributed, such as a ship or a country. A male person, and sometimes a male animal, is referred to using he. In other cases it can be used. The word it can also be used as a dummy subject, in sentences like It is going to be sunny this afternoon.

The third-person plural forms such as they are sometimes used with singular reference, as a gender-neutral pronoun, as in each employee should ensure they tidy their desk. Despite its long history, this usage is sometimes considered ungrammatical.

The possessive determiners such as my are used as determiners together with nouns, as in my old man, some of his friends. The second possessive forms like mine are used when they do not qualify a noun: as pronouns, as in mine is bigger than yours, and as predicates, as in this one is mine. Note also the construction a friend of mine (meaning "someone who is my friend").

Demonstrative and Interrogative

The demonstrative pronouns of English are this (plural these), and that (plural those), as in these are good, I like that. Note that all four words can also be used as determiners (followed by a noun), as in those cars. They can also form the alternative pronominal expressions this/that one, these/those ones.

The interrogative pronouns are who, what, and which (all of them can take the suffix -ever for emphasis). The pronoun who refers to a person or people; it has an oblique form whom (though in informal contexts this is usually replaced by who), and a possessive form (pronoun or determiner) whose. The pronoun what refers to things or abstracts. The word which is used to ask about alternatives from what is seen as a closed set: which (of the books) do you like best? (It can also be an interrogative determiner: which book?; this can form the alternative pronominal expressions which one and which ones.) Which, who, and what can be either singular or plural, although who and what often take a singular verb regardless of any supposed number.

All the interrogative pronouns can also be used as relative pronouns; see below for more details.

Relative

The main relative pronouns in English are who (with its derived forms whom and whose), which, and that.

The relative pronoun which refers to things rather than persons, as in the shirt, which used to be red, is faded. For persons, who is used (the man who saw me was tall). The oblique case form of who is whom, as in the man whom I saw was tall, although in informal registers who is commonly used in place of whom.

The possessive form of who is whose (the man whose car is missing ...); however the use of whose is not restricted to persons (one can say an idea whose time has come).

The word that as a relative pronoun is normally found only in restrictive relative clauses (unlike which and who, which can be used in both restrictive and unrestrictive clauses). It can refer to either persons or things, and cannot follow a preposition. For example, one can say the song that [or which] I listened to yesterday, but the song to which [not to that] I listened yesterday. The relative pronoun that is usually pronounced with a reduced vowel, and hence differently from the demonstrative that. If that is not the subject of the relative clause, it can be omitted (the song I listened to yesterday).

The word what can be used to form a free relative clause – one that has no antecedent and that serves as a complete noun phrase in itself, as in I like what he likes. The words whatever and whichever can be used similarly, in the role of either pronouns (whatever he likes) or determiners (whatever book he likes). When referring to persons, who(ever) (and whom(ever)) can be used in a similar way (but not as determiners).

"There"

The word there is used as a pronoun in some sentences, playing the role of a dummy subject, normally of an intransitive verb. The "logical subject" of the verb then appears as a complement after the verb.

This use of there occurs most commonly with forms of the verb be in existential clauses, to refer to the presence or existence of something. For example: There is a heaven; There are two cups on the table; There have been a lot of problems lately. It can also be used with other verbs: There exist two major variants; There occurred a very strange incident.

The dummy subject takes the number (singular or plural) of the logical subject (complement), hence it takes a plural verb if the complement is plural. In informal English, however, the contraction there's is often used for both singular and plural.

The dummy subject can undergo inversion, Is there a test today? and Never has there been a man such as this. It can also appear without a corresponding logical subject, in short sentences and question tags: ''There wasn't a discussion, was there? There was.''

The word there in such sentences has sometimes been analyzed as an adverb, or as a dummy predicate, rather than as a pronoun. However, its identification as a pronoun is most consistent with its behavior in inverted sentences and question tags as described above.

Because the word there can also be a deictic adverb (meaning "at/to that place"), a sentence like There is a river could have either of two meanings: "a river exists" (with there as a pronoun), and "a river is in that place" (with there as an adverb).

Other

Other pronouns in English are often identical in form to determiners (especially quantifiers), such as many, a little, etc. Sometimes, the pronoun form is different, as with none (corresponding to the determiner no), nothing, everyone, somebody, etc. Many examples are listed as indefinite pronouns. Another indefinite (or impersonal) pronoun is one) (with its reflexive form oneself and possessive one's), which is a more formal alternative to generic you.

Verb

A verb is a word that expresses an action, a state, or an occurrence — and it's the engine of every English sentence. Understanding how verbs work is foundational to everything else in English grammar, from forming questions to building complex sentences.

Verb Forms

Most English verbs have five inflected forms:

• Base form (go, write, climb) — used as an infinitive, imperative, present subjunctive, and present indicative in all persons except third-person singular.
• -s form (goes, writes, climbs) — used for the present tense, third-person singular (she writes).
• Past tense (went, wrote, climbed) — also called the preterite.
• Past participle (gone, written, climbed) — identical to the past tense for regular verbs, but often different for irregular verbs.
• -ing form (going, writing, climbing) — serves as the present participle and gerund.

The verb be is a special case with more forms than any other English verb (am, is, are, was, were, been, being). Modal verbs like can, must, and should have fewer forms than typical verbs.

Main Verbs and Auxiliaries

Verbs in English often appear in combinations: one or more auxiliary verbs paired with a main verb.

• The dog was barking very loudly.
• My hat has been cleaned.
• Jane does not really like us.

The first verb in the combination is the finite verb (it carries tense and agrees with the subject). The rest are nonfinite (infinitives or participles). Notice that these verbs don't always sit next to each other — as in does not really like.

Tense, Aspect, and Mood

English expresses tense (time reference), aspect (how an action unfolds over time), and mood (the speaker's attitude toward the action) mostly through verb combinations rather than word endings. That's why you'll encounter labels like "present progressive" or "conditional perfect" — these are specific tense–aspect–mood combinations built with auxiliaries.

Self-check: If you can change the time of a sentence by swapping one word (She runs → She ran), that word is the verb.

Keep Practising

To build your verb skills from the ground up, try these challenges: Basics. "To be" in Present Tense, Basics. Common Uses of Auxiliary Verbs, and Transitive and Intransitive Verbs.

A2 | Elementary | Pre-intermediate

CEFR A2 is the second level in the Common European Framework of Reference for Languages, often called elementary or pre-intermediate. If you're at this stage, you've moved beyond the basics of A1 and can handle simple, real-life communication — but you're still building the foundations you'll need for B1 and beyond.

What can an A2 learner do?

At A2, you can:

• Understand everyday expressions related to familiar topics — personal details, family, shopping, work, and your local area.
• Communicate in routine situations that involve a simple, direct exchange of information (e.g. ordering food, asking for directions, making small talk).
• Describe your background and immediate environment in simple terms — where you live, what you do, what you need.
• Read and understand short, simple texts like signs, menus, timetables, and brief personal messages.

Key grammar at A2

At this level, you're expected to be comfortable with several core grammar areas:

• Past simple and past continuous — talking about completed actions and actions in progress in the past.
• Present perfect — connecting past events to the present (I've visited London twice).
• Basic modal verbs — expressing ability, permission, necessity, and possibility (can, must, should, have to).
• Common question forms — both simple and slightly more complex (How long have you lived here?).
• Articles and determiners — using a/an/the correctly, along with words like some, any, few, little.
• Basic conditionals — first conditional and simple uses of if and wish.

You're also expanding your vocabulary through collocations (natural word pairings like make a decision or take a break) and learning to use gerunds and infinitives with common verbs.

How A2 differs from A1 and B1

Compared to A1, A2 learners can do more than just produce isolated phrases — you can link simple sentences and participate in short conversations. Compared to B1, you're still relying on familiar contexts and predictable language; handling unexpected topics or expressing opinions in detail comes at the next level.

Self-check: If you can describe your daily routine, talk about past experiences, and handle a basic conversation at a shop or restaurant — but struggle when the topic gets abstract or unfamiliar — you're likely at A2.

Practice at this level

Try these challenges to test and strengthen your A2 skills: Is your English level A2/Pre-intermediate? Test your English CEFR Level!, Basics. Present Perfect., and Basics. Common More Complex Questions..

B1 | Intermediate

B1 is the intermediate level of the Common European Framework of Reference for Languages (CEFR). It marks the point where you move beyond survival English and start expressing yourself with real independence — describing experiences, explaining opinions, and handling everyday situations without a script.

What a B1 user can do

At this level, you're expected to:

• Understand the main points of clear, standard speech and writing on familiar topics — work, school, travel, hobbies.
• Handle most travel situations in English-speaking environments.
• Produce simple connected text on topics you know or care about.
• Describe experiences, events, hopes, and plans, and give brief reasons and explanations for your opinions.
• Communicate in routine tasks that require a straightforward exchange of information.

What B1 grammar looks like

B1 is where grammar starts to get more layered. You're not just forming basic sentences anymore — you're combining ideas, using different tenses with more precision, and starting to handle structures like the passive voice, modal verbs for necessity and possibility, and gerunds vs. infinitives. You're also expected to build complex sentences with linking words and dependent clauses.

Typical B1 grammar areas include:

• Future tenses — distinguishing will, going to, and the present continuous for future plans
• Passive voice — The report was written yesterday.
• Modal verbs — You should apply early. / She might be late.
• Used to — I used to live in Berlin.
• Verb patterns — knowing whether a verb takes a gerund, an infinitive, or both (I enjoy reading vs. I decided to leave)

What B1 doesn't mean

B1 speakers still hesitate, make grammatical errors, and sometimes struggle with less familiar topics. That's normal. The key difference from A2 is that you can keep a conversation going and get your point across even when things aren't perfect. The step up to B2 involves handling more abstract topics, understanding nuance, and producing more complex, accurate language.

Self-check: Can you tell a friend about a recent trip — what happened, what you liked, and what you'd do differently — without switching to your native language? If yes, you're likely operating at B1 or above.

Ready to find out where you stand? Try Are you B1/Intermediate? Test your English CEFR Level to figure out!, then build your skills with challenges like Basics. Passive Voice, Basics. Modal verbs, and Used to.

Difficulty: Medium

Medium difficulty. Difficulty levels represent author's opinion about how hard a question or challenge is.