Sign in means to enter an account, website or app with your login details; it's the same as log in. The second meaning is to record your arrival at a building: write your name in a book or sign at reception in an office, school or hospital. When you leave, you sign out.
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sign in (to + account/app/website); sign in with + email/Google; sign in at + reception; sign-in (noun): the sign-in page
- I can't sign in to my bank app because it keeps asking for a new code.
- You can sign in with your Google account instead of creating a new password.
- All visitors have to sign in at reception and wear a badge in the building.
What changed
First versionI tried to sign in my account three times, but the password didn't work.
RevisionI tried to sign in to my account three times, but the password didn't work.
The particle in in sign in doesn't mean “into the account”. It's part of the verb, and the place you're signing in to is introduced with to: sign in to my account, sign in to the app. Only to was added.
Don't confuse sign in with sign up. Sign up means to register, create an account or enrol on a course: I signed up for the course last week. Sign in means to get into something you're already registered for. The noun is hyphenated: the sign-in page.
Your turn
When you arrive at the office, please ___ at reception, and don't forget to sign out when you leave.
Show the answer
sign in — At reception you record your arrival, and when you leave you sign out, so you need sign in. Sign up means to register or enrol, and you don't do that every time you come to the office.
Write about a service you couldn't sign in to. Say what the service was and what helped you get in.
I couldn't sign in to my university portal last night, so I reset my password and got in straight away.
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