英文grammer(unless ,so that....)

1. Coordinate conjunctions
Coordinate conjunctions are used to join two similar grammatical constructions; for instance, two words, two phrases or two clauses.
e.g. My friend and I will attend the meeting.
Austria is famous for the beauty of its landscape and the hospitality of its people.
The sun rose and the birds began to sing.

In these examples, the coordinate conjunction and is used to join the two words friend and I, the two phrases the beauty of its landscape and the hospitality of its people, and the two clauses the sun rose and the birds began to sing.

The most commonly used coordinate conjunctions are and, but and or. In addition, the words nor and yet may be used as coordinate conjunctions. In the following table, each coordinate conjunction is followed by its meaning and an example of its use. Note the use of inverted word order in the clause beginning with nor.

Coordinate Conjunctions
and: in addition She tried and succeeded.but: however They tried but did not succeed.or: alternatively Did you go out or stay at home?nor: and neither I did not see it, nor did they.yet: however The sun is warm, yet the air is cool.
As illustrated above, when a coordinate conjunction joins two verbs which have the same subject, the subject need not be repeated. For instance, in the example she tried and succeeded, the pronoun she acts as the subject for both the verb tried and the verb succeeded. It should also be noted that when a coordinate conjunction joins two verbs which do not have the same subject, the two coordinate clauses may be separated by a comma or semicolon, in order to make the meaning clear.

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