A group of us writers were discussing capitalization last week. Some were unclear about when to capitalize family names and endearments. I went to the internet and here’s what I found.

Capitalize nouns like mom, dad, and grandmother when they are used as PROPER nouns.  Example, “Dad, can I use the car?” (So, basically Dad is being used in place of his name).

However, when preceded by an article or a possessive noun, don’t capitalize. That means if the words a, an, the, my, your, our precede the noun, no capital is needed. Example, “My dad let me borrow the car.

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But what about other words used in place of a person’t name? Words such as honey, sweetheart, darling, dear, son, and so on? 

Well, that is the confusing one. I read several opinions—each of which had different answers and reasons behind them. But, if you go by what The Chicago Manual of Style says, then here is the answer: Capitalize nicknames, but not terms of endearment (unless they begin a sentence.)  
Example: If you consistently call someone, Pookie, then that is their nickname, so capitalize it.
Example: “Where’s the toothpaste, dear?” Dear is not capitalized because it is a term of endearment and not a nickname.

Since this “rule” lies in a gray area, the most important thing is this: Use your best judgement, but be sure to be consistent throughout your entire article, book, etc.

Hope this helps if, like me, you were stressing out about this “rule” of grammar.