Capitalization: Family Relationships (when used as proper names)

When terms denoting family relationships are used as proper nouns (i.e. as names), they are capitalized.

Mom, Dad wants to know when dinner will be ready.

Please give this book to Uncle Mark.

Pass the peas, please, Grandfather.

Hey, Sis. What are you doing?

Auntie Joan is my favourite aunt.

When the terms are used as common nouns (i.e. not as a name), they’re not capitalized. Generally, there will be a possessive pronoun (my, her, his, our) or an article (the, a, an) in front of the common noun.

My mom and dad want me to be home by 10:00 at night.

Next week, I’m going to the museum with my uncle, Mark.

Please pass the peas to your grandfather.

The two sisters went shopping together.

Auntie Joan is my favourite aunt.