Types of Sentences (Compound Sentences)

We may form Compound Sentences by:

1. Using a Comma and a Joining Word (For, And, Nor, But, Or, Yet, and So) 

The teacher lectured for over an hour, and his students slept soundly.
The students studied hard, for they feared they might fail the test. 
Aminah had a test the next day, so she studied all night long.

Subject + Predicate, joining word Subject + Predicate.

2. Using a Semicolon.

The teacher lectured for over an hour; his students slept soundly.
The students studied hard; they feared they might fail the test.
Aminah studied all night long; she had a test the next day.

Subject + Predicate ; Subject + Predicate.

3. Using a Semicolon, a Transition Word (however, therefore, in fact, on the other hand, nonetheless, besides, instead, then, moreover, similarly, nevertheless, etc.) and a Comma.

The flower was beautiful; however, it smelled awful. 
Salmah did all her homework; then, she went to sleep. 
Ali studied for the test all weekend; therefore, he expected a good grade on the test.

Subject + Predicate ; transition word, Subject + Predicate.