Why does "thank you card" not have a hyphen? --- Tom sent a thank you email and a few pictures Thank you!
You mean as opposed to "thank-you card"? I'm guessing because "thank you" is generally written without one, so when you add more words to it, you don't change how you write it. I don't know for sure, this could very well just be one of the inexplicable idiosynchracies of the English language that you just have to learn.
That's not what generally happens if the two words have the function of an adjective: http://owl.english.purdue.edu/owl/resource/576/1/ Use a hyphen to join two or more words serving as a single adjective before a noun: a one-way street chocolate-covered peanuts well-known author
I wasn't making a generalization, I was speaking about this specific case. "Thank you" isn't generally used as an adjective while "one-way" "chocolate-covered" and "well-known" are. Also see my point about idiosynchratic use. At some point, I think this starts to become a question along the same lines as "why is the past tense of 'eat' 'ate' instead of 'eated'?".
there's another thread here that deals with hyphens in great detail and many examples... i suggest you go there to pursue this, instead of wasting time/space on another thread about what's already been dealt with pretty thoroughly... https://www.writingforums.org/showthread.php?t=40019&highlight=hyphens
Thanks, mammamaia, I read the thread, but I still don't know if "thank-you card" is more correct than "thank you card" because I see (and find arguments for) both.