A complex sentence is a sentence that contains one independent clause and at least one dependent clause.

Here are three examples of complex sentences with two different dependent clauses (one subordinate and one relative, or two different types of subordinates):

Example 1:

“Because the rain was heavy, the game, which had been scheduled for hours, was canceled.”

Dependent 1 (Adverbial): “Because the rain was heavy” (explains why)

Dependent 2 (Relative): “which had been scheduled for hours” (adds extra info about the game)

Independent: The game was canceled.

Example 2:

“Although she studied hard, she failed the test that her teacher had warned her about.”

Dependent 1 (Adverbial): “Although she studied hard” (contrasting clause)

Dependent 2 (Relative): “that her teacher had warned her about” (describes the test)

Independent: She failed the test.

Example 3:

“When the alarm sounded, the workers, who were still in the building, evacuated immediately.”

Dependent 1 (Adverbial): “When the alarm sounded” (time clause)

Dependent 2 (Relative): “who were still in the building” (describes the workers)

Independent: The workers(s) evacuated(v) immediately(adv). [7]

Example 4:

After the concert ended, just before Andrew showed, we quickly hid everything.”

You are combining two introductory adverbial phrases that are both subordinate to the same main clause:

Dependent Clause #1: “After the concert ended”

Dependent Clause #2: “(just) before Andrew showed”

Main Independent Clause: “we quickly hid everything”

Example 1: (Adverbial + Noun Clause)

“After the meeting ended, everyone realized that the plan would not work.”

Dependent 1 (Adverbial – Time): “After the meeting ended”

Dependent 2 (Noun Clause – Object): “that the plan would not work”

Independent: Everyone realized [noun clause].

Example 2: (Conditional + Adverbial Clause)

“If you leave now, you’ll arrive before the concert starts.”

Dependent 1 (Conditional – “If” clause): “If you leave now”

Dependent 2 (Adverbial – Time): “before the concert starts”

Independent: You’ll arrive.

Example 3: (Concessive + Purpose Clause)

“Even though she was tired, she stayed up so that she could finish her project.”

Dependent 1 (Concessive – Contrast): “Even though she was tired”

Dependent 2 (Purpose – “So that” clause): “so that she could finish her project”

Independent: She stayed up.

Example 4: (Reason + Result Clause)

“Because the roads were icy, the school closed early so that students could get home safely.”

Dependent 1 (Reason – “Because” clause): “Because the roads were icy”

Dependent 2 (Result – “So that” clause): “so that students could get home safely”

Independent: The school(s) closed(v). [early](adv)

After the concert ended, which was their final performance, the band celebrated since they were finally on vacation.”

Independent Clause: the band celebrated

Dependent Clause 1: After the concert ended (shows time)

Dependent Clause 2 (nonessential relative clause describing the head dependent): which was their final performance (adds description)

Dependent Clause 3: since they were finally on vacation (shows reason)