The following verbs can be followed by -ing or to .. . with no difference of meaning:
begin start continue intend bother
So you can say:
- It started raining. or It started to rain.
- Andy intends buying a house. or Andy intends to buy ...
- Don't bother locking the door. or Don't bother to lock ...
But normally we do not use -
ing after -
ing:
- It's starting to rain. (not It's starting raining)