‘Help do’ vs ‘Help doing’

(Found at Jakub Marian’s page - https://jakubmarian.com)

Both “help someone do something” and “help someone to do something” are acceptable. The form without “to” seems to be more common in everyday speech than the form with “to” (especially in American English), but both forms are common in formal writing:

correct He helped me move to London. (more common)

correct He helped me to move to London. (less common)

Some learners try to combine the -ing form we can find in other phrases (such as “go doing something”) with “help”, but this is unfortunately not correct:

correct He helped me (to) move to London.

wrong He helped me moving to London.

Finally, there is one informal phrase in which we do use “help doing”, namely “cannot help doing”. If someone “cannot help doing something”, they cannot suppress the need to do it. For example:

I can’t help thinking about her constantly. = I must think about her constantly. I cannot stop thinking about her.

This idiom means the same as “cannot help but do”—we could also say, “I cannot help but think about her constantly.”