The correct answers are "There was few water left in my bottle, so I bought more." and "We met a few nice locals, but little of them spoke English."
Water is uncountable, so use little (not few). In the second error, locals is countable, so use few (not little). Remember: few/a few → countable nouns; little/a little → uncountable nouns.
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.
Quantifier
Quantifier vs determiner: quantifiers ARE a type of determiner — they sit before nouns and specify "how much/many." The distinction matters because quantifiers are constrained by countability: many only with countable, much only with uncountable. Other determiners (the, this, my) don't have this restriction.
A quantifier = vague amount before a noun (all, some, any, many, few, much, little, several, each, every). Must match noun countability.
Diagnostic: is the noun countable? → many/few/several. Uncountable? → much/little. Unsure about the noun? → check if you can say one ___, two ___s.
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 A2–B1 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.