Possible action - see if it succeeds) action may not be possible – see if you can do it)

Try exercising, you may lose weight. David tried to win the race, but failed.

Try remembering his telephone number. Try to remember his telephone number.

(It would be a good idea!) (Please, do it; it’s important!)

to be sorry

gerund + for infinitive

(to apologize for an earlier action) (to apologize for a present action)

I am sorry for shouting at you this morning. Sorry to interrupt, but can I ask you a question?

to be afraid