既然你在這裡, 那我們就開始吧。

As long as you are here, we might as well begin.

Since you are here, we might as well begin.

Source: Tatoeba

Sentence Composition

1 既然 rán since; as; this being the case
=2 you (informal, as opposed to courteous nín)
=2 you (Note: In Taiwan, is used to address females, but in mainland China, it is not commonly used. Instead, is used to address both males and females.)
3 zài
  1. to exist; to be alive
  2. (of sb or sth) to be (located) at
  3. (used before a verb to indicate an action in progress)
4 這裡 zhè here
=5 surname Na
=5 Nuó surname Nuo
=5 variant of
=5
  1. (specifier) that; the; those (colloquial pr. nèi)
  2. (pronoun) that (referring to persons, things or situations)
  3. then (in that case)
=5 nuó
  1. (archaic) many
  2. beautiful
  3. how
  4. old variant of nuó
6 我們 men we; us; ourselves; our
7 jiù
  1. (after a suppositional clause) in that case; then
  2. (after a clause of action) as soon as; immediately after
  3. (same as 就是 jiùshì) merely; nothing else but; simply; just; precisely; exactly
  4. only; as little as
  5. as much as; as many as
  6. to approach; to move towards
  7. to undertake; to engage in
  8. (often followed by zhe) taking advantage of
  9. (of food) to go with
  10. with regard to; concerning
  11. (pattern: jiù ... ...) even if ... still ...
  12. (pattern: ... jiù ...) if not ... then must be ...
8 開始 kāishǐ
  1. to begin
  2. beginning
  3. to start
  4. initial

classifier:

=9
  1. bar (loanword) (serving drinks, or providing Internet access etc)
  2. to puff (on a pipe etc)
  3. (onom.) bang
  4. abbr. for 貼吧 tiē
=9 ba
  1. (modal particle indicating suggestion or surmise)
  2. ...right?
  3. ...OK?
  4. ...I presume.
=9 biā (onom.) smack!
=9 only used in 吧呀