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Authentication vocabularyphrasal verb · /saɪn ɪn/

sign in

In simple English

To authenticate or log in to a computer system, network, or online account, typically using credentials like a username and password or SSO.

Someone wants to understand what 'sign in' means when using work tools or discussing authentication.

At a glanceCEFR A2–B1
Commonness
Versatility
FormalityCasualFormalNeutral
Spoken ↔ WrittenSpokenWrittenBoth
Directness ↔ DiplomaticDirectDiplomaticNeutral
Region

Say it like this

Can you sign in and check if the issue is still there?
I can't sign in — it keeps saying my password is wrong.
You need to sign in with your work email, not your personal one.
Just sign in and I'll share the screen.
Sign in to Jira and create a ticket for this bug.

Real examples

Standup

"I couldn't sign in to the staging environment yesterday, so I'll try again this morning."

Slack message

"Can you sign in to the admin panel and check the user permissions?"

GitHub PR

"Users will need to sign in before they can access the new dashboard feature."

Jira ticket

"Bug: Users cannot sign in after password reset. Error message: 'Invalid credentials.'"

Retrospective

"We lost time because half the team couldn't sign in to the new testing tool."

Sprint planning

"This story covers the SSO integration so users can sign in with their company accounts."

Pair programming

"Let me sign in to my account so we can test with my permissions."

Don't say this

I need to sign in into the system.
I need to sign in to the system.Sign in already includes the direction. Use 'sign in to', not 'sign in into'.
Please sign in me to the portal.
Please sign me in to the portal.The object (me) goes between 'sign' and 'in' when using a pronoun.
I signin to GitHub every morning.
I sign in to GitHub every morning.'Sign in' is two words when used as a verb. 'Sign-in' (hyphenated) is a noun or adjective.

Other forms

verb (base)

sign in

"Please sign in to continue."

verb (present)

signs in

"She signs in every morning at 9."

verb (past)

signed in

"I signed in but the page still showed an error."

verb (-ing)

signing in

"I'm having trouble signing in."

noun

sign-in

"The sign-in process takes too long."

adjective

sign-in

"We need to fix the sign-in page."

Often used with

sign in toThe standard preposition after sign in
sign in withUsed when specifying credentials (e.g., sign in with Google)
sign-in pageThe page where users enter credentials
sign-in flowThe entire authentication process
single sign-inLess common variant of single sign-on (SSO)
sign-in credentialsThe username and password used to authenticate

Similar words

log inInterchangeable with sign in; slightly more technical
authenticateMore formal/technical; often used in documentation
log onOlder term, more common in IT support contexts
accessBroader meaning; doesn't always imply credentials

Opposites

sign outlog outlog offdisconnect

Practice

Try it

4 quick exercises

Choose the most natural sentence

1. How would you ask a teammate to check something in a system?

Find the error

2. I signin to Jira every morning to check my tickets.

Complete the sentence

3. Users will need to sign ___ with their Google accounts to access the dashboard.

Rewrite more naturally

4. The authentication to the system is not working for me.

More words

Questions

Quick poll

Have you said "sign in" in a standup this week?

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