Because, When, Although

Subordinating conjunctions that make complex sentences, and transitions like although and since.

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 39

Some joining words start a part of a sentence that can't stand alone: because, when, although, if, after, before, since, and until.
Because it was raining can't stand alone. Join it to a sentence: We stayed inside because it was raining. Now it's a complex sentence!
When that part comes first, put a comma after it: When the bell rings, line up at the door.
Although shows a surprise. Although it was cold, we played outside. You might expect them to stay in, but they didn't!

Georgia's K-12 English Language Arts Standards:

3.L.GC.1.39 — Grammar: Use subordinating conjunctions to join clauses. (Introduce)
3.T.SS.1.c — Use conjunctions and transition words or phrases, such as although and since, to add cohesion and link ideas and information. (C)
3.L.GC.2.b — Use a variety of simple, compound, and complex sentences to strengthen clarity and coherence, establishing consistent verb tense within and between sentences. (C)