Are “Sister” And “Brother” Capitalized? Full Explanation

Generally, we do not capitalize familial titles like “sister” or “brother.” However, there are some cases where you might, and it would help to know when these cases apply. This article will explain all you need to know about capitalizing the two words.

Are “Sister” And “Brother” Capitalized?

“Sister” and “brother” are not typically capitalized. We do not need to capitalize them because they are standard nouns to identify our siblings. Usually, they come with a possessive pronoun (i.e., “my brother”). However, if used as a title, you do capitalize them.

sister and brother capitalized

The key differences come from whether they’re titles or not. There really aren’t that many cases where “sister” or “brother” are used as a title unless you come from a very strict family that addresses each other by their relation.

  • Sister, I would like to talk to you.
  • Not now, Brother. Maybe later.

As you can see, the above examples are capitalized because we’re referring to “sister” and “brother” as titles.

Nine times out of ten, you will not need to do this. It’s much more likely to see the words appear in the following cases:

  • My brother will be here shortly.
  • This is my sister.

When Should I Capitalize “Sister” And “Brother”?

Let’s go a little more into detail about when “sister” and “brother” get capitalized. This should help you understand how rare it is.

“Sister” and “brother” are capitalized only when used as titles. That means you are addressing the person as either “Sister” or “Brother.” This usually does not apply unless you have a strict familial code about names and titles.

Sometimes, you might find “Sister” is the first word of a longer title name. This applies to religious circles (i.e., nuns). You might come across a “Sister Margaret,” where “sister” is capitalized because it’s her official title.

When Should I Not Capitalize “Sister” And “Brother”?

In most cases, you do not need to capitalize the two words. They are simple nouns, which means we do not use capital letters in most cases.

“Sister” and “brother” are nouns we typically use with a possessive word. Therefore, we do not need to capitalize them. Instead, we can write a possessive pronoun before them to show who “owns” the sibling in the sentence.

It is much more likely for us to use “sister” and “brother” as nouns rather than proper nouns. You’ll find that the uncapitalized variations are more common in English, and most natives would expect you to leave them uncapitalized.

Examples Of How To Use “Sister” And “Brother” Capitalized In A Sentence

While it’s not standard practice, that doesn’t mean it isn’t correct. We can capitalize both words, and it looks like the following examples.

  1. Brother, I need to talk to you about this performance.
  2. I haven’t got time for you right now, Sister. Leave me alone.
  3. I’m sorry, Brother. I did not mean to upset you.
  4. Sister Harriet said that I could go out tonight if I behaved myself.
  5. Brother, I think it’s time we had that discussion.
  6. Oh, Sister, I’m so sorry you feel like that.
  7. Stop it, Brother. It’s not funny.

“Sister” and “Brother” are rarely capitalized. We only use them with capitals when they are titles or honorifics. Since this isn’t standard practice in English, you’re better off keeping them uncapitalized.

Examples Of How To Use “Sister” And “Brother” Uncapitalized In A Sentence

Now let’s show you what is more likely to be seen. “Sister” and “brother” are not typically capitalized words, and it would help for you to understand their correct forms from the examples below.

  1. My brother is coming to see me today.
  2. I have a brother, but he isn’t all that interested in any of my favorite things.
  3. Your sister has a foul mouth, and she should be told off.
  4. I can’t get over my sister telling me those awful things about you.
  5. I haven’t got a sister anymore.
  6. You should apologize to your brother for saying those things.
  7. I found my sister to be difficult to live with, but now I miss her.

“Brother” and “sister” are standard and common nouns. We do not capitalize them when we are talking about our siblings in a general tone rather than specifically referring to their titles.

Do The Same Rules Apply To Capitalizing All Family Titles?

There are other family titles that we might come across. Typically, all of them follow the same capitalization rules, though there are some that are more common to capitalize than others.

Titles like “Mom” and “Dad” are common to capitalize. We do this because it’s common for us to refer to them by their titles when we are talking to them. However, when using possessive pronouns, we would keep them uncapitalized.

There are plenty of other examples we could give, but we feel like “mom” and “dad” helps us to explain most of it.

If you use them as titles, you might see them as follows:

  • Listen, Mom. I don’t think you should go out there to talk to him.
  • Okay, Dad. I’m really sorry you had to go through that alone.

As you can see, when referring to titles, we always capitalize the words. Also, it’s much more likely to capitalize “mom” and “dad” compared to “brother” and “sister” because it’s more traditional for us to refer to them by these titles.

If possessive pronouns are used, we would instead see this:

  • My mom doesn’t want me talking to you anymore.
  • I have to tell my dad about this!

As you can see, when using other pronouns, there is no need to capitalize the words. That’s because “mom” and “dad” are treated like standard nouns and objects in the sentences.

Quiz: Have You Mastered The Capitalization Of “Sister” And “Brother”?

Finally, let’s see whether you’ve mastered the differences with a quick quiz.

  1. My (A. sister / B. Sister) didn’t want anything to do with me.
  2. Hello, (A. brother / B. Brother). Have you come to gloat some more about this?
  3. Why thank you, (A. sister / B. Sister). I’ll be sure to repay you for this kindness.
  4. Stop calling my (A. brother / B. Brother) an idiot! He’s better than you’ll ever be!
  5. I’m really sorry, (A. sister / B. Sister). Please forgive me.

Quiz Answers

  1. A
  2. B
  3. B
  4. A
  5. B

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