complex sentence
A sentence with one independent clause and at least one dependent clause.
subordinating conjunction
A word or phrase that starts a dependent (adverb) clause and shows how it connects to the main idea: because, although, unless, so that, whereas, once.
subordination
Putting a less important idea in a dependent clause so that the main idea stands out in the independent clause.
concession
Admitting a point before making your main point: Although the trail was muddy, the hike was worth it.
condition
Something that must happen for something else to happen: If it freezes tonight, the rink will open.