Choose the correct word to complete the sentence.
šø After three months of daily practice, Jamie is finally getting good ___ the guitar.
The correct answer is at playing.
After the adjective "good" + the preposition at, use a gerund (-ing form). The pattern is: be good at + gerund.
Gerund
If you've ever said I enjoy to read or good at to swim and wondered why it sounded wrong, you've met the gerund. English is fussy about which structures take -ing and which take to + verb, and getting this wrong is one of the most common giveaways that someone learned grammar from a list rather than from real usage.
A gerund is the -ing form of a verb acting as a noun ā reading, swimming, being late. After many common verbs (enjoy, avoid, finish) and after every preposition, English demands the gerund, never the infinitive.
Infinitive
If you've ever written I enjoy to swim or He let me to go and only later learned why both are wrong ā you've hit the infinitive's main puzzle. English is fussy: some verbs demand the to-infinitive, some demand the bare infinitive, some demand the gerund, and a few accept multiple options with different meanings (remember to lock vs remember locking).
The infinitive is the basic form of a verb, used non-finitely. The to-infinitive (to go) follows verbs like want, decide, plan; the bare infinitive (go) follows modal verbs (can, will) and causatives (Let him go).
Preposition
If you've ever written I'm interested on you (should be in) or I'm good on football (should be at) ā you've hit prepositions' main pitfall. Their choice is mostly idiomatic, not logical, and rarely matches what your native language does. Memorising the right preposition for each common verb and adjective is what stops your speech from sounding subtly off.
A preposition is a small word linking a noun or noun phrase to other parts of the sentence: in, on, at, to, from, with. Marks time, place, manner, or abstract relationships. Choice is largely idiomatic, especially in fixed combinations (depend on, good at, afraid of).
B1 | Intermediate
If you can hold a conversation about your weekend, explain why you're late, and follow a short news story without panicking ā but still feel lost in fast or technical English ā you're probably operating at B1. Knowing this matters: study material at the wrong level either bores you or burns you out, and B1 is the typical target for travel, casual work, and most everyday social English.
B1 is the intermediate level in the CEFR framework, where you handle everyday English independently and start combining ideas with complex sentences, passive voice, and modal verbs.
Difficulty: Medium
If easy questions feel too obvious but hard questions leave you guessing, you're probably ready for Medium ā the level where most real learning happens. It pushes just enough to expose the rules you don't quite have yet, without burying you in edge cases. This is where steady fluency is built, one well-aimed challenge at a time.
The Medium difficulty tag marks middle-range challenges ā typically A2 to B1. One rule per question, realistic distractors, and contexts that require active thought rather than instant recognition.