Understand the difference between main and subordinate clauses and that a complex sentence involves at least one subordinate clause (ACELA1507)
knowing that complex sentences make connections between ideas, such as: to provide a reason, for example He jumped up because the bell rang.; to state a purpose, for example She raced home to confront her brother.; to express a condition, for example It will break if you push it.; to make a concession, for example She went to work even though she was not feeling well.; to link two ideas in terms of various time relations, for example Nero fiddled while Rome burned.
knowing that a complex sentence typically consists of a main clause and a subordinate clause