Time Clauses with before, after, and when

·        A time clause explains when something happened. It begins with one of the following before, after, and when.  ·        Use a comma after the time clause.

·        We can also use these time clauses after the main clause. ·        If it comes after the main clause it doesn’t need a comma.

Before she ate, she washed her hands.

She washed her hands before she ate.

After she used the toilet, she washed her hands.

She washed her hands after she used the toilet.

When she was washing her hands, she dropped the soap.

She dropped the soap when she was washing her hands.

Here is a video on time clauses, although it focuses on the future it explains the time clauses well.