Complement means that something goes well with something else or is a complete amount. A good way to remember this is that complement and complete both have E's. For example:
- Ice cream complements cake.
- The team had its full complement of players.
Compliment is a word of praise. If something is complimentary, it is free. For instance:
- It it nice to receive a compliment.
- The bank gave out complimentary pens to people opening a new account.