In the above example the main clause is relativized.
A topic sets off background information that will be discussed in the following main clause.
Information may also be added after the main clause as a kind of 'afterthought'.
The check replied, The main clause may contain a verb in the passive voice.
It relies on a main clause to give it meaning.
The main clause makes sense on its own.
But the subject of the main clause is "the stalled car".
A conjunctive adverb is also used in a single main clause.
The subject of the main clause and the verb in the infinitive must be identical.
As for its word order, it differs in two things only from a main clause: