Lesson 3.4: Subject-Auxiliary Inversion and Fragments
Distinguishing subordinate clauses from independent clauses is an important aspect of learning not to write in fragments, since one of the most common types of stigmatized fragments in writing is a subordinate clause. Consider, for example, the following complex sentence.
The monkey can see that the banana is ripening.
This sentence contains two clauses: the independent clause and the subordinate clause, that the banana is ripe, contained within it. Apply SAI, and you get
Can the monkey __ see that the banana is ripening?
Employing SAI picks out the independent clause subject, the monkey. Even though the banana is also a subject (of the subordinate clause), SAI will not work with that subject since the banana is not the subject of the independent clause.
*The monkey can see that is the banana __ ripening?
SAI is, therefore, a useful test to determine whether a sentence has the subject that is required in much formal writing. When SAI is attempted with a sentence without an independent clause subject, it's terrible.
Because he does not like it. → *Because does he not like it?
SAI fails here since because introduces a subordinate clause and there is no independent clause subject. Similarly for other kinds of fragments, SAI will not work since there is no subject.
At the skateboard store. → ??
There is no auxiliary verb and there is no way to turn this into a question.
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