Page 39 - Prep Demo

prepositions are always followed by an object
the preposition’s object is the noun or pronoun that follows the preposition
Aziz shut the door before his walk.
there is an object after before - the noun walk so in this case before is a preposition
Aziz shut the door before he left.
there is no noun as an object after before - left is a verb so in this case before is not a preposition
the before in the second sentence is a subordinating conjunction prepositions that act as subordinating conjunctions - such as
before, after, since, as and until are covered in a separate unit
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