cocoricot posted:Can you tell me what "that'' means?
Hardly a day went by that I didn't think about her.
Hello, Coco,
"That" doesn't mean anything. It is simply a complementizer introducing the relative clause "that I didn't think about her," which modifies "day," even though it is separated from that noun by the verb phrase "went by."
If you want to use a relative adverb instead of that, "when" is fine. I just think the sentence sounds a little bit better with "that." Notice that the sentence relates to a question such as the one below, in which you have four options:
- Were there any days that you didn't think about her?
- Were there any days when you didn't think about her?
- Were there any days on which you didn't think about her?
- Were there any days you didn't think about her?