Αν μία πρόθεση ακολουθείται από ρήμα, τότε το ρήμα τελειώνει σε -ing:

• Are you interested in working for us?
• I am not very good at learning languages.
• Sue must be fed up with studying.
• What are the advantages of having a car?
• Thanks very much for inviting me to your party.
• How about meeting for lunch tomorrow?
• Why don't you go out instead of sitting at home all the time?
• Carol went to work in spite of feeling ill.