Mom, mother, or my Mom?: The Chicago Guide to Family Titles

In fiction and nonfiction alike, kinship names quietly communicate intimacy, culture, and endearments. The Chicago Manual of Style (CMOS) treats family terms with more nuance than most writers realize, and getting them right can instantly level up your prose.

Let’s break down how kinship names work, when they’re capitalized, and why the smallest choices can completely shift the tone of your narrative.

Photo by cottonbro studio

Kinship Names: Small Words, Big Impact

Family titles do a lot of heavy lifting. A single word (mother versus Mom) can tell readers how close characters are, how formal the situation feels, or whether a relationship is loving or strained. Under The Chicago Manual of Style, kinship terms function in two main ways, proper names (treated like names) or descriptions (treated like common nouns). Which role they play determines capitalization, punctuation, and even emotional subtext. And yes, readers notice—even if they can’t explain why something feels “off.”

Capitalization: When Family Titles Become Names

According to CMOS, capitalize kinship names when they are used as a direct replacement for a person’s name. Think of it this way: If you could swap the word with an actual name, it probably gets a capital letter.

Examples:

Mom wanted me to visit my brother Charlie in Romania.

While having dinner, Dad said he would take me to Disney Land.

Yesterday, Aunt Rose arrived early from the airport.

Here, Mom, Dad, and Aunt function as names. Capitalization signals familiarity and emotional closeness. It’s giving family-group-chat energy.

Lowercase When They’re Just Descriptions

When kinship terms describe a relationship rather than act as names, they stay lowercase. This usually happens when the term follows a possessive (my mother, his aunt), an article (the sister), or other modifiers that frame the relationship instead of directly addressing the person.

Examples:

My mother called me before sunrise, her voice steady but urgent.

She spoke to her dad afterward, filling him in on what had happened.

For years, his aunt lives overseas, a constant presence in family stories.

See how they’re lowercased here? In those sentences, the kinship terms are being used descriptively, not as a name. Lowercasing creates distance. It’s more neutral, sometimes more formal, and often used in reflective narration or emotionally complex scenes. Writers use this contrast intentionally to show shifting dynamics.

Direct Address Changes Everything

If a character is speaking directly to a family member, capitalize the kinship term—even in dialogue because it functions as a proper name in that moment. Direct address turns the title into a stand-in for the person’s actual name, signaling familiarity and immediacy.

Examples:

“Can you help me, Dad?” Ana said, pushing the stack of books across the table.

“I told you already, Grandma. I will take care of you.” Peter smiled. 

But notice this:

“My dad doesn’t understand,” she said.

Direct address turns the word into a name. CMOS is very clear on this, and once you see it, you can’t unsee it. These kinship terms become impossible to read the text the same way. It’s one of those small details that immediately makes writing feel precise.

Writing with Intention

Kinship names are small choices with big impact. They signal intimacy or distance, shape character relationships, and influence tone without exposition. The key is always consistency. Decide how your writing refers to family members and stick with it—unless the emotional context changes. When it does, that shift can be powerful. During revisions, watch for unintentional capitalization changes. If Mom becomes my mother halfway through a chapter, ask yourself why. Sometimes it’s a mistake. Sometimes it’s the moment the relationship cracks. Both are worth noticing.

Final Thoughts

This is easy to master. Kinship names aren’t about memorizing rules. It’s important to understand how language reflects relationships because word choices form connection. CMOS gives you the framework, but you decide the emotional story. Because details matter, and readers feel them, even when they can’t explain why.

If you’ve finished your manuscript and want to be sure your kinship terms (and everything else) are working exactly the way you intend, we’re here to help. Send your manuscript to themanuscripteditor.com for a complimentary 800-word sample edit.