Is “because” a subordinating conjunction?
Yes, because is a subordinating conjunction. It is used to introduce a dependent clause that gives a reason for/cause of something (e.g., “The picnic is canceled because rain is forecast”).
Note that the phrase because of is not a subordinating conjunction. It functions as a preposition meaning “on account of” (e.g., “The picnic is canceled because of the rain”).
The QuillBot Grammar Checker can help ensure you’re using subordinating conjunctions and prepositions correctly.