50%

Help the stranded astronaut finish her optimistic transmission to Earth by choosing the correct option.

"Don't worry about me! I still have _____ oxygen tanks left, which gives you plenty of time to send a rescue ship."

The correct answer is a few.

"Oxygen tanks" is a countable plural noun, so we need few or a few. Because the astronaut is optimistic and has enough tanks to survive until rescue, we use a few (which has a positive meaning: "some"). If she said few, it would mean she was almost completely out of air!

To ChallengesPreviousNext

Determiner

Determiner vs adjective: both appear before a noun, but determiners specify which/how many while adjectives describe what kind. Determiners come first: the big cat (✅) vs big the cat (❌). You can stack adjectives (big fluffy cat) but generally only one determiner per noun.

A determiner is a function slot before a noun filled by articles, demonstratives, possessives, or quantifiers.

Diagnostic: does the word tell you which one or how many rather than what kind? → determiner. Does it describe a quality? → adjective.

Countable and uncountable

Countable vs uncountable: countable nouns can be numbered and pluralised (one book, two books). Uncountable nouns can't (information, not informations). The distinction determines your choice of article, quantifier (much/many, few/little), and whether the noun can be plural.

Countable = takes a/an, has a plural, uses many/few. Uncountable = no a/an, no plural, uses much/little. Some nouns are both depending on meaning (coffee = the substance vs a coffee = a cup).

Diagnostic: can you say one ___, two ___s? Yes → countable. No → uncountable (use a unit phrase: a piece of, a bit of).

A2 | Elementary | Pre-intermediate

A2 vs B1: A2 handles routine transactions and simple past narration. B1 handles connected discourse, explaining reasons, and understanding main points in clear standard speech. If you can tell what happened but not why it matters, you're still A2.

A2 is the elementary level of the CEFR: past simple, present perfect, first conditional, basic modals, and routine communication about familiar topics.

Diagnostic: can you link ideas with because, although, so that and hold a conversation beyond scripted topics? No → A2. Yes → moving into B1.

Medium

Medium vs Easy: Easy has one obviously correct answer and clearly wrong distractors. Medium has one correct answer but plausible distractors — you need to actually know the rule, not just guess from sound.

The Medium tag filters for A2B1 challenges with realistic difficulty: one rule per question, plausible alternatives, everyday contexts.

Diagnostic: if you're scoring 90%+ on Easy, move here. If you're below 60% on Medium, go back to Easy for that topic. Target 70–80% accuracy for maximum learning.