You don't always have to say "I love you,"
although that is wonderful and necessary, too.
Your love can also be expressed by:
Smiling at a person you love when he/she comes home.

Saying "I'm sorry" even when it is easier to keep quiet.
Hugging a person you love.
Complimenting a person you love.
Offering to help a person you love.
Picking up a small gift for someone you love.
Little things say "I love you."