They are words which typically go before noun phrases or pronouns.
Examples :
- He walks beside me.
- There are some foods in the fridge.
- The bank is next to supermarket.
If a verb comes after a preposition (in, at, with, about, etc.), the verb ends in -ing.
Here are another example of sentences using prepositions :
- Are you interested in working for us.
- I'm not very good at learning languages.
- I'm fed up with studying.
- The children are excited about going on holiday.
- What are the advantages of having a car?
- This knife is only for cutting bread.
- John went to work in spite of feeling ill.
- I bought a new bicycle instead of going away on holiday.