A century ago, it was standard to write any time as two words in all contexts. But it’s now perfectly acceptable to write anytime as one word when you’re using it as an adverb. However, some readers still consider it a casualism, so you may want to stick to the two-word version for extremely formal writing.
- When in doubt, write any time as two words. It might look a little old-fashioned, but it won’t be wrong.
- Anytime is an adverb that means “whenever” or “at any time.” You can use it like you would any other adverb: Call me anytime. Call me often. Call me quickly.
- You can’t use anytime with a preposition like at. If you have a preposition, you need the two-word version: They could call at any time.
- You also need the two-word version when you’re talking about an amount of time: Do you have any time to speak to us today?
When is anytime one word?
You can write anytime as one word or as two words when you are using it as an adverb.
If you’re not sure whether you’re using anytime as an adverb, try substituting some other adverb like “quickly” or “loudly.” My new bicycle allows me to go anywhere quickly. If the adverb works, then it’s OK to make anytime one word. You can also make it two words, but to some readers it will look old-fashioned or more formal.
You can also use anytime (or any time) as a conjunction.
There’s no difference in meaning.
When is any time two words?
There are a couple of cases where you have to make any time two words.
Any time has to be two words when you use it with a preposition like “at.”
You also have to make any time two words when you’re talking about an amount of time.