Help the wildlife photographer finish his field notes by dragging the correct verbs to complete the funny story.
I was hiding in the bushes when I noticed a large, fluffy bear trying to sneakily open a camper's picnic basket. A few minutes later, I observed the clumsy animal trip over a fallen log and roll all the way down the hill.
I was hiding in the bushes when I noticed a large, fluffy bear trying to sneakily open a camper's picnic basket.
When you catch someone (or a bear!) in the middle of doing something, use a verb of perception (like notice) followed by the -ing form. The bear was already in the process of trying to open the basket when the photographer noticed.
A few minutes later, I observed the clumsy animal trip over a fallen log and roll all the way down the hill.
For a quick action that you witness from beginning to end, use the bare infinitive. The bear tripped and rolled as one complete, unfortunate sequence of events!
Verb
A verb is a word that expresses an action, a state, or an occurrence — the engine of every English sentence. Most verbs have five forms: base (go), -s form (goes), past tense (went), past participle (gone), and -ing form (going). The verb be is the major exception with eight forms; modal verbs like can and must have fewer.
Verbs carry tense (when), aspect (how it unfolds), mood (the speaker's attitude), and voice (active vs passive). Mastering them is foundational — virtually every other grammar topic depends on getting verbs right.
Gerund
A gerund is the -ing form of a verb used as a noun — swimming, reading, being late. It can sit in any position a noun can: as the subject (Swimming is fun), as the object of a verb (I enjoy swimming), or as the complement of a preposition (She's good at swimming).
Gerunds matter because dozens of common English verbs and almost every preposition force you into the -ing form. Pick the wrong shape — I enjoy to swim, good at to swim — and the sentence sounds clearly off to a native speaker. Knowing which contexts demand a gerund (vs. an infinitive) is what makes verb patterns click.
Infinitive
The infinitive is the basic, unmarked form of a verb, used when no tense or subject agreement is needed. English has two flavours: the to-infinitive (to swim, to read) and the bare infinitive (swim, read). The to-infinitive follows verbs like want, decide, hope, plan (I want to swim); the bare infinitive follows modal verbs (I can swim) and certain causative verbs (Let him go).
Knowing which form to use after which verb is one of the trickiest distinctions in English — closely tied to the parallel choice of gerund (-ing form). I want to swim but I enjoy swimming aren't interchangeable.
Participle
A participle is a verb form that doubles as an adjective or adverb. English has two: the present participle ending in -ing (running, sitting) and the past participle (broken, gone, written). Both build tenses (is running, has gone), but they also stand alone modifying nouns (the broken window) or verbs (Exhausted, we fell asleep).
Participles look like simple parts of speech but pull double duty — most learner errors come from confusing the present participle with the gerund (also -ing but acting as a noun) or the past participle with the past tense.
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.