Remember that a dependent clause always contains a subject and a verb, but it cannot stand by itself. 1  Adverb clauses provide information about what is going on in the main (independent) clause: where, when, or why. 2  Adjective clauses work like multi-word adjectives. 3  Noun clauses can do anything that nouns can do.
An alternate juror is a spare, not unlike the spare tire for your car that rides along with you wherever you drive but is only used if one of your regular tires fails. Similarly, an alternate juror sits and listens to evidence just like the other jurors but only deliberates and votes if one of the sitting jury members is unable to serve.
Related to juror: jury duty jury, n a certain number of citizens selected according to law and sworn to inquire of certain matters of fact and to declare the truth on evidence submitted to them.