Yes, that is exactly what you should tell them. 1  If two clauses are connected with a coordinating conjunction, it's a compound sentence. 2  If two clauses are connected with a subordinating conjunction, it's a complex sentence.
Trains were first- 1784, but cars weren't invented until 1890.
AT A GLANCE: Joshua Lionel Cowen was an inventive guy and had always been very interested in trains. In 1901, he fitted a small motor under a model of a railroad flatcar, powered by a battery on 30 inches of track and the Lionel electric train was born. The first Lionel train was designed to attract window-shopping New Yorkers using the power of animated display.