cosign

/ˈkō-ˌsīn/ (ame, mw)

cosign — verb

  • cosignpresent simple I / you / we / they
  • cosigns3rd person singular
  • cosigning-ing form
  • cosignedpast simple

1. to put your name on a legal or official paper together with at least one other p

1.動詞及物B2
釋義

to put your name on a legal or official paper together with at least one other person, showing that you all agree to what the document says

例句

Ola and her brother agreed to cosign the rental agreement for their shared apartment.

cosign + [document] for shared responsibility

Both company directors cosigned the contract after reviewing every clause carefully.

cosign + [contract/agreement] after review

同義詞
  • countersign

    more formal; often used for verifying an already-signed document in official or military contexts

  • endorse

    broader meaning; can mean signing the back of a cheque or publicly supporting something

文法句型

cosign + [document]

cosign + [document] + with + [person]

用法筆記

Unlike 'sign', which a single person can do alone, 'cosign' always involves at least two people signing the same document together.

常見錯誤

Ola cosigned with the rental agreement.
Ola cosigned the rental agreement.
💡'cosign' takes the document as its direct object, not the preposition 'with'.

2. to sign a loan agreement or rental contract on behalf of someone else, promising

2.動詞及物 / 不及物B2
釋義

to sign a loan agreement or rental contract on behalf of someone else, promising to pay the money back if that person fails to do so, so that the lender accepts their application

例句

Hassan's parents agreed to cosign his student loan so he could attend university.

cosign + [loan] to help someone qualify

Kavya asked her aunt to cosign the lease for her first apartment in Taipei.

cosign + [lease] for a rental property

同義詞
  • guarantee

    broader legal term; a guarantee can be a separate document rather than signing the same one

  • vouch for

    less formal; implies recommending someone's reliability rather than taking financial liability

反義詞
  • default on

    the opposite action — failing to pay, which is what the cosigner promises to prevent

文法句型

cosign + [loan/lease]

cosign + for + [person]

cosign + [person]'s + [loan/lease]

用法筆記

The person who cosigns is legally responsible for the entire debt if the main borrower fails to pay. This sense is most common in banking, rental, and loan contexts.

常見錯誤

I cosigned my friend a loan.
I cosigned my friend's loan.' or 'I cosigned for my friend's loan.
💡'cosign' takes the loan/lease document as object, or 'for + person'.

3. to openly express agreement with a person's idea, plan, or action, thereby givin

3.動詞及物C1
釋義

to openly express agreement with a person's idea, plan, or action, thereby giving it your visible backing in a public way

例句

Several well-known professors cosigned the open letter opposing the new education policy.

cosign + [open letter/statement] for public endorsement

Lan cosigned her colleague's proposal during the staff meeting and offered to help develop it.

cosign + [proposal] in a meeting context

同義詞
  • endorse

    more common and can be formal or commercial; 'endorse a product' but not 'cosign a product'

  • back

    less formal; implies active help, not just verbal agreement

  • support

    broader and more general; 'cosign' specifically implies adding your name publicly

反義詞
  • oppose

    to actively disagree with someone's position

  • reject

    to refuse to accept someone's idea or plan

文法句型

cosign + [statement/opinion/decision]

cosign + [person]'s + [decision/plan]

用法筆記

This is a figurative extension of the literal signing sense — you are not actually signing paperwork, but lending your name to support a position. Common in workplace and public discourse.