“Anytime” is a relatively new word—yes, we’re calling early 20th century “recent” for the sake of this linguistic argument. And you know that any time there is a new word, there’s going to be a grammarian hullaballoo. Here’s just another example.
“Anytime” (one word) is considered a casual form, not one for your résumé or emails to advance you up the corporate ladder. In fact, this one-word form is still not recognized by some dictionaries. (I’m looking at you, OED). “Anytime” technically is defined as an adverb meaning “whenever” or “on any occasion,” but as a new word, it is young and defiant, having other meanings too. “Anytime” can also simply mean “No problem,” in response to a “thank you.”
If you aren’t sure if you can get away with “anytime” vs. “any time,” ask yourself if you can replace the word in question with “at any time.”
- When are you free for coffee?
- Anytime. (Correct. Answering “at any time” would also make sense here.)
- Does dinner Tuesday work?
- Sure, anytime after six. (Correct. Answering “at any time after six” would also make sense.
- Do you have anytime to take a walk with me? (Incorrect. Do you have “at any time” to take a walk with me” doesn’t make sense. The adjective-noun pairing “any time” (two words) is needed here.)
I can go further with this one, but I’ll stop there.
“Any time” (two words) is admittedly the standard form. If you’re ever concerned about which form you should choose, experts argue you’ll never go wrong by using the two-word combination. I’m not sure I completely agree with that, but then again, I’m American and therefore a linguistic rebel at heart. Or so the argument goes. (The casual “anytime” is apparently much more common on this side of the Atlantic.)
Personally, do I dare to use the non-standard form? Anytime I can. Take that, Oxford English Dictionary.