Verb Patterns

Gerunds after Prepositions

One rule to remember

A gerund is a verb + -ing that behaves like a noun. Prepositions are followed by nouns — so when a verb follows a preposition, it must be a gerund.

preposition + verb + -ing — never a to-infinitive

He was able to manage by asking for help.

She put on her hat without saying a word.

The test: if you could put it or something after the word, that word is a preposition — so use -ing. good at it → good at making sculptures.

Five patterns

Pattern	Example
preposition + gerund	He managed by asking* for help.*
two-word preposition + gerund	They took a break instead of starting* their design.*
verb + preposition + gerund	He apologized for missing* the meeting.*
phrasal verb + gerund	We ended up buying* our clothes online.*
adjective + preposition + gerund	She is very good at making* sculptures.*

More examples: except for being on call · talk about starting a business · kept on asking · interested in going to the party.

Collocations worth memorizing

Most errors are not grammar errors — they are missing collocations. Learn these as whole chunks, preposition included.

Type	Chunks
verb + preposition	apologize for, believe in, insist on, succeed in, dream of, worry about, think about, object to
phrasal verbs	give up, end up, keep on, put off, look forward to, get around to
adjective + preposition	good / bad at, interested in, afraid of, tired of, worried about, keen on, capable of, responsible for
two-word prepositions	instead of, except for, in spite of, as well as, apart from, before / after

She finally gave up smoking last year.

I'm tired of waiting for an answer.

In spite of losing the first game, they won the tournament.

The to trap

This is where nearly everyone slips. To has two completely different jobs. As an infinitive marker it is followed by the base verb; as a preposition it is followed by a gerund.

I want to go. → to = infinitive marker

I look forward to going. → to = preposition

These expressions all end in a preposition to, so a gerund must follow: look forward to, be used to, get used to, object to, be committed to, in addition to, be opposed to.

Don't confuse: He used to work nights (a past habit — base verb) and He is used to working nights (he is accustomed to it — gerund). Different structures, different meanings.

⚠ Common mistakes:
✗ I look forward to hear from you. → ✓ to hearing from you
✗ She is good at to cook. → ✓ good at cooking
✗ They left instead of to wait. → ✓ instead of waiting
✗ He left without say goodbye. → ✓ without saying goodbye
✗ Thank you for help me. → ✓ for helping me
✗ He's responsible checking the invoices. → ✓ responsible for checking

Match the Sentence Halves

Click a sentence beginning on the left, then click the preposition + gerund phrase that completes it.

Matched 0 / 5

Fill in the Gaps

Complete each sentence with the correct form of the verb in brackets.

Find the Mistake

One sentence, four underlined parts. Click the lettered part that contains the error — it is not always in the grammar of this lesson, so read the whole sentence.

Put the Words in Order

Click the words to build the correct sentence. Click a placed word to remove it.

Answer the Questions

Write your own answers using a preposition + gerund. Then click "Show Model Answer" to compare.