Remember that what might be acceptable in everyday speech could still be considered sloppy on paper. For example, many people use the word aggravate when they mean to use irritate. Aggravate means to make worse; irritate means to exasperate or inflame. Notice the difference:

Wrong: His careless driving aggravated his date.

Right: His careless driving irritated his date.

Wrong: The cold weather irritates my grandmother's arthritis.

Right: The cold weather aggravates my grandmother's arthritis.

Confusing these words may irritate your English teacher and aggravate a low grade.