你一旦不做个乖孩子，圣诞老人就不会来噢。

As soon as you start misbehaving, Father Christmas will not come to see you.

Source: Tatoeba

Sentence Composition

=1 你 nǐ you (informal, as opposed to courteous 您 nín)
=1 你 nǐ you (Note: In Taiwan, 妳 is used to address females, but in mainland China, it is not commonly used. Instead, 你 is used to address both males and females.)
2 一旦 yīdàn
  1. in case (sth happens)
  2. if
  3. once (sth happens, then...)
  4. when
  5. in a short time
  6. in one day
3 不 bù
  1. no; not so
  2. (bound form) not; un-
4 做 zuò
  1. to make; to produce
  2. to write; to compose
  3. to do; to engage in; to hold (a party etc)
  4. (of a person) to be (an intermediary, a good student etc); to become (husband and wife, friends etc)
  5. (of a thing) to serve as; to be used for
  6. to assume (an air or manner)
=5 个 gě used in 自个儿 zìgěr
=5 个 gè
  1. (classifier used before a noun that has no specific classifier)
  2. (bound form) individual
=5 个 gè variant of 个 gè
6 乖 guāi
  1. (of a child) obedient, well-behaved
  2. clever
  3. shrewd
  4. alert
  5. perverse
  6. contrary to reason
  7. irregular
  8. abnormal
7 孩子 háizi child
8 圣诞老人 Shèngdàn Lǎorén Father Christmas; Santa Claus
9 就 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 着 zhe) taking advantage of
  9. (of food) to go with
  10. with regard to; concerning
  11. (pattern: 就 jiù ... 也 yě ...) even if ... still ...
  12. (pattern: 不 bù ... 就 jiù ...) if not ... then must be ...
10 不会 bùhuì
  1. improbable
  2. unlikely
  3. will not (act, happen etc)
  4. not able
  5. not having learned to do sth
  6. (coll.) (Tw) don't mention it
  7. not at all
11 来 lái
  1. to come
  2. (used as a substitute for a more specific verb)
  3. hither (directional complement for motion toward the speaker, as in 回来 huílai)
  4. ever since (as in 自古以来 zìgǔyǐlái)
  5. for the past (amount of time)
  6. (prefix) the coming ...; the next ... (as in 来世 láishì)
  7. (between two verbs) in order to
  8. (after a round number) approximately
  9. (used after 得 dé to indicate possibility, as in 谈得来 tándelái, or after 不 bù to indicate impossibility, as in 吃不来 chībulái)
=12 噢 ō
  1. oh; ah (used to indicate realization)
  2. also pr. òu
=12 噢 yǔ
  1. Sentence-final particle used to indicate an admonishing tone.
  2. Sentence-final particle used to indicate an informative tone.
  3. only used in 噢咻
  4. only used in 噢咿