20%

Help the friendly alien complete his letter home about Earth by dragging the correct prepositions into the blanks.

Dear Mom,

Earth is strange! Humans travel long distances by train instead of using their own wings. In fact, they are very bad at flying without machines. To eat, they pick up food with a metal tool called a fork. I am reading a big book about their funny habits so I can fit in!

Love,
Zorg

Dear Mom,

Earth is strange! Humans travel long distances by train instead of using their own wings.

We use by to talk about general methods of transport (e.g., by train, by car, by bus) when there is no article (a/the) before the noun.

In fact, they are very bad at flying without machines.

The adjective "bad" (and "good") is followed by the preposition at when talking about skills or abilities.

To eat, they pick up food with a metal tool called a fork.

We use with to indicate the tool or instrument used to perform an action.

I am reading a big book about their funny habits so I can fit in!

We use about to introduce the subject or topic of a book, story, or conversation.

To ChallengesPreviousNext

Preposition

  • interested in — ❌ interested on
  • good at football — ❌ good in football
  • depend on — ❌ depend of
  • arrive at the station — ❌ arrive to the station

Prepositions link nouns to the rest of the sentence: time (at 5pm), place (in London), manner (with care), abstract (afraid of). Most are idiomatic — the "correct" preposition must be memorised with each verb/adjective combination.

Rule: there is no universal rule. English prepositions are learned by combination: interested IN, good AT, depend ON, afraid OF. Your native language's equivalent will often mislead.

Adjective

  • a tall building — ❌ a tally building
  • The soup is hot — ❌ The soup is hotly
  • a lovely small old table — ❌ a small lovely old table
  • She seems tired — ❌ She seems tiredly

These bolded words are adjectives — words that describe nouns or pronouns. They sit before a noun (a tall building) or after a linking verb (The soup is hot).

Pattern: if a word can slot between a/the and a noun (a ___ thing) and can take -er/-est, it's almost certainly an adjective.

Gerund

  • I enjoy reading. — ❌ I enjoy to read.
  • She's good at swimming. — ❌ She's good at to swim.
  • He avoids making eye contact. — gerund after avoid
  • Running is good exercise. — gerund as subject

A gerund is the -ing form of a verb functioning as a noun. It follows verbs like enjoy, avoid, finish, mind and ALL prepositions. Never use an infinitive where a gerund is required.

Rule: after a preposition (at, in, of, about, without) → always gerund. After enjoy, avoid, finish, mind, suggest, deny → always gerund.

Collocations

  • make a decision — ❌ do a decision
  • strong coffee — ❌ powerful coffee
  • heavy rain — ❌ strong rain
  • highly unlikely — ❌ very unlikely (grammatical, but less natural)

Collocations are word pairs that English habitually puts together. Both options may be grammatically valid, but one sounds native and the other doesn't.

Pattern: there's no logic to predict them — you make decisions but do homework, you have strong coffee but heavy rain. They must be learned as chunks, not deduced from rules.

A1 | Elementary | Beginners

  • My name is Anna. — present simple of be
  • Where is the station? — basic *wh-*question
  • I have two brothers. — possession with have
  • She likes coffee. — third-person -s

These are A1 sentences — the starting level of the CEFR framework. At A1 you can introduce yourself, ask and answer simple personal questions, and handle basic everyday transactions using present tense, be/have/do, and core vocabulary.

If you can say these but freeze at normal speaking speed, you're solidly A1 — and that's exactly where to start.

Medium

  • If I were you, I would apologise. — one rule (second conditional), but distractors like was tempt you
  • Answers require active thought, not instant pattern recognition
  • Vocabulary and context are realistic, not artificially simplified
  • Usually tests one rule, but the wrong answers are plausible

Medium marks middle-difficulty challenges: A2B1, one rule tested, but with realistic distractors that require genuine understanding.

Use "Medium" when Easy feels too obvious but Hard feels overwhelming. This is where most productive learning happens — the sweet spot of difficulty.