Combine sentence and use coordinate conjection:

1) my bus driver is strict .
she is friendly.
( compund sentence )

2) the engine sputtered.
then it died
( compund verb )

Coordinating conjunctions include for, and, nor, but, or, yet, and so.  
 
To connect the following sentences using coordinating conjunctions, you can say:
1.    She is friendly, but my bus driver is strict. (The coordinating conjunction used here is “but”.) However, for this sentence to make sense, there has to be a preceding sentence that can further expound the antecedent of the pronoun “she”.

2.    The engine sputtered, and then it died. (The coordinating conjunction used here is “and”.)