我們是老朋友。

We're friends from way back.

We're old friends.

Source: Tatoeba

Sentence Composition

1 我們 wǒmen we; us; ourselves; our
=2 是 shì
  1. to be (followed by substantives only)
  2. correct; right; true
  3. (respectful acknowledgement of a command) very well
  4. (adverb for emphatic assertion)
=2 是 shì variant of 是 shì
3 老朋友 lǎopéngyou
  1. old friend
  2. (slang) period
  3. menstruation