People log in to Facebook.

In this sentence, if I change log in to log-in, will it be grammatically incorrect? Or the adding/omission of a hyphen is just a matter of style?

The other thing is, if log in is listed in dictionaries as a phrasal verb and log-in is not listed as a phrasal verb, will citing the dictionaries be a sufficient reason to say that adding a hyphen in log in is grammatically incorrect?

2 Answers 2


In formal English, adding the hyphen to log in makes your sample sentence grammatically incorrect.

The hyphen has the effect of turning the phrasal verb into an adjective or a noun. For example, these sentences are valid:

Click here to go to the log-in page.

Upon successful log-in, you will be redirected to the subscription page.

This rule mostly applies to more formal usage. I would say your average native English speaker is entirely unaware of how hyphens work with phrasal verbs.

In practical usage, especially on the Internet, "log in" is often shortened to "login," and "login" is often used as a noun, adjective, or verb.

Here's a good page on hyphenation of phrasal verbs:


  • 3
    I sadly have to agree with the statement about native English speakers not understanding hyphens in phrasal verbs. I've been surprised several times when people I know couldn't distinguish "Log in" from "Log-in/Login" and other similar terms, when I personally feel it makes a big difference.
    – Harris
    Oct 16, 2017 at 17:28
  • 2
    Funny story, I just asked my father what the difference between login and log-in is. He does the NYT crossword every day, so I figured he would be a good person to ask. He knew that to "wake up" wouldn't take a hyphen, but that a "wake-up call" would. But he couldn't explain why. I think there are probably a lot of people like that.
    – Ringo
    Oct 16, 2017 at 17:37
  • Related: Could it also be "log into"?
    – Barmar
    Oct 16, 2017 at 18:43
  • @Barmar Ask that as a separate question.
    – anon
    Oct 16, 2017 at 18:45
  • @Barmar I would say "Log Onto" is not a common phrasal verb. I have never seen "log onto" or "log-onto." I have seen "log-on," but that is almost an outdated variation of "log-in."
    – Ringo
    Oct 16, 2017 at 19:04

[Quick answer to be cleaned up later...]

Phrase was originally, "Please log into the system." Or reaching back further "Please log on to the system". Through speech, people dropped the preposition at the end believing the context was already implicit in their situation. This yielded "Could you log in again, Joe?" And "Log in with your username."

At some point, the datum entered when attempting to login became the login - a noun. it likely coexisted with the form "log-in" as many new nouns do initially.

Presently, i see two relevant questions regarding the verb "to login": which spelling is least ambiguous and which spelling is most popular?

  • 1
    preposition, not proposition
    – Barmar
    Oct 16, 2017 at 19:06

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