I give you....absolutely nothing

I really wish I could be giving you more today.

But my head and my day are completely filled with this kind of stuff:

hence, the clause introduced by who does serve to tell which people are meant; in these sentences the clauses introduced by which and when are nonrestrictive, and in this dependent clause an introductory phrase requires to be set off by a comma.....

Editing. It's like algebra, in letters.