What is an aaawwuubbis?

AAAWWUUBBIS is an acronym to remember the most common subordinating conjunctions: Although, After, As, While, When, Until, Because, Before, If, and Since. If a clause begins with an AAAWWUUBBIS word (subordinating conjunction), it becomes a dependent clause.

For example:

I went to the store.

(Independent clause. This is a complete sentence.)

When I went to the store...

(Dependent clause. This is not complete without a comma and an independent clause.)

When I went to the store, I saw my friend.

(Dependent clause + comma + independent clause. This is again a complete sentence.)