Maxsus ta’lim vazirligi nizomiy nomidagi Toshkent davlat pedagogika universiteti qoshidagi akademik litsey Nurmatov J. N, Kudratov K. X

before a conjunction (and, but, for, or) connecting sentences or full clauses, and between very short clauses that are not connected by a conjunction

He hadn’t worked very hard, but still did well in the exams.

I came, I went home, I came back again.

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  sometimes in informal sentences when that is omitted
  

She runs so fast, no one can catch her.

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  to show that a word or words used earlier in the sentence have been left out
  

Indoor sports are preferred by some; outdoor sports, by many others.

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  to separate direct speech from words identifying the speaker and type of speech