Can since be used in the beginning of sentence?

"Since" can be used at the beginning of a sentence, but it usually introduces a dependent clause, meaning it needs to be followed by an independent clause to form a complete sentence.

Example:

* Since it was raining, we decided to stay inside.

Here, "Since it was raining" is a dependent clause, and "we decided to stay inside" is the independent clause.

However, "since" can also be used as an adverb meaning "ago," in which case it can stand alone at the beginning of a sentence.

Example:

* Since last year, we've learned a lot about this topic.

In this case, "since" functions as an adverb, modifying the phrase "last year."

Therefore, whether "since" can be used at the beginning of a sentence depends on the context and how it is used.