when it comes to something/to doing something

when it comes to (someone or something)

When considering some particular person, thing, or action. John is a bit of a blowhard, but when it comes to pushing sales, no one in the company is better. There's nothing she doesn't know when it comes to computers. He's a sweet guy, but he's a bit useless when it comes to kids.
See also: come
Farlex Dictionary of Idioms.

when it comes to something

as for something; speaking about something. When it comes to fishing, John is an expert. When it comes to trouble, Mary really knows how to cause it.
See also: come
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

when it comes to

Also, if or when it comes right down to . As regards, when the situation entails. For example, When it comes to renting or buying, you'll spend about the same amount. It is also put as when it comes down to it or that , as in If it comes right down to it, they said you could visit any time you're able to, or When it comes to that, we can lend you the fare. This idiom uses come to in the sense of "amount to" or "be equivalent to." [Second half of 1700s]
See also: come
The American Heritage® Dictionary of Idioms by Christine Ammer.

when it comes to something/to doing something

when it is a question of something: When it comes to getting things done, he’s useless.
See also: come, something
Farlex Partner Idioms Dictionary
See also:
  • when it comes to
  • when it comes to (someone or something)
  • 60
  • be pushing (an age)
  • be pushing 40, 50, etc.
  • push out
  • pushing
  • blowhard
  • push by
  • run (up) a tab