The correct answers are The main computer crashed, and it refuses to reboot., I lost my favorite wrench, but I think it is under the console., and The spaceship is old, but it still flies perfectly.
Slavic languages assign grammatical gender (masculine, feminine, neuter) to inanimate objects, leading speakers to accidentally call a computer "he" or a wrench "she." In English, almost all inanimate objects and concepts take the neutral pronoun it.
Pronoun
A pronoun is a small, closed class of words that stands in for a noun or noun phrase. The main types: personal (I, you, he, she, it, we, they) plus their object (me, him) and possessive (my, mine) forms; demonstrative (this, that); relative (who, which, that); interrogative (who, what); and reflexive (myself, yourself).
Pronouns are how English avoids endlessly repeating names. The catch: their meaning depends entirely on context, so unclear pronoun reference (Tom told Mike that he was wrong — who's he?) is one of the most common writing problems.
Subject
The subject is the part of a sentence or clause that tells you who or what the sentence is about. It's typically a noun, pronoun, or noun phrase that comes before the verb and controls the verb's form: She works (singular) vs They work (plural).
The subject isn't always the doer of the action — in passive sentences, it receives the action (The window was broken). English also uses dummy subjects like it and there that hold the subject slot without carrying real meaning (It is raining; There are problems). Spotting the real subject is what makes subject-verb agreement automatic.
Sentence
A sentence is the largest grammatical unit in writing — one or more clauses expressing a complete thought, ending with a period, question mark, or exclamation mark. English sentences come in four structural types: simple (one independent clause), compound (two or more independent clauses joined), complex (independent + dependent clause), and compound-complex (multiple independent + dependent clauses).
Mastering sentence types is what lets you vary rhythm in writing. All-simple sentences read as choppy; all-complex sentences read as dense. Mixing them is what makes prose breathe.
B1 | Intermediate
B1 is the intermediate level in the CEFR framework — the point where you stop relying on memorised phrases and start handling everyday English independently. At B1 you can describe experiences, explain opinions, and follow most clear standard speech on familiar topics like work, travel, and hobbies.
Grammatically, B1 means combining tenses with precision, building complex sentences, and starting to use passive voice, modal verbs for necessity and possibility, and verb patterns (gerund vs. infinitive). Knowing your level shapes what you study next: pushing too far ahead frustrates you; staying below your level wastes time.
Difficulty: Medium
The Medium difficulty tag marks questions and challenges in the middle of the difficulty range — typically suitable for A2 to B1 learners. Expect a single rule with realistic distractors, longer sentences, and contexts where you have to think before answering rather than reading off the obvious choice.
Filter by Medium when you're past the absolute basics and ready to consolidate. It's the level where most lasting progress happens — easy enough that you can finish without exhausting concentration, hard enough that getting it right means you've actually understood.