I. verbs can be followed by '-ing' or 'to ~': begin, start, continue, intend, bother (e.g. It has started raining. or It has started to rain.)
a. But normally we do not use '-ing' after '-ing'. (e.g. It's starting to rain. (not It's starting raining))
I1. Some verbs can be followed by '-ing' or 'to ~' with a different of meaning
a. Remember: I remember doing something = I did it and now I remember this. (e.g. I know I locked the door. I clearly remember locking it.) vs. I remembered to do something = I remembered that I had to do it, so I did it. (e.g. I remembered to lock the door, but I forget to shut the windows.)
b. Regret: I regret doing something = I did it and now I'm sorry about it. (e.g. I now regret saying what I said. I shouldn't have said it.) vs. I regret to say/ to tell you/ to inform you = I'm sorry that I have to say (etc.) (e.g. (from a formal letter) We regret to inform you that we cannot offer you the job.)
c. go on: Go on doing something = continue with the same thing. (e.g. The president paused for a moment and then went on talking.) vs. Go on to do something = do or say something new (e.g. After discussing the economy, the president then went on to talk about foreign policy.)
Idiom 365
Pulling One's Leg: is not true as a way of joking or deceive someone playfully
Example: They decided to pull the customer’s leg by telling him that they wanted to have a test.