Japanese - 家族 （かぞく）Family

In Japanese talking about family is a little more complicated than it is in English.

Firstly, there are two words for certain family members. Also, you must be specific about your OLD brother or sister as opposed to your YOUNGER brother or sister.

★ First I will give you a list of words that you use in TWO situations ― 1) When speaking about another person's family; and 2) Titles you use for family members (ie the words you use to call your mom, dad,  siblings, etc.) These are honorific expressions, so in order to show respect to other's family, OR to speak to your own family, you use these words.

Father = お父さん　（おとうさん）

Mother = お母さん　（おかあさん）

Older brother = お兄さん　（おにいさん）

Older sister = お姉さん　（おねえさん）

Grandfather = おじいさん

Grandmother = おばあさん

※ NOTE that there are no words for younger siblings in this category. This is because for aunts, uncles, younger siblings, and other extended family there is only one word, regardless of context.

Here are some example of proper and improper use of these words.

CORRECT USAGE 

✔ やまださんの　おとうさんは　アメリカに　います。 = Yamada's father is in the US.

       Since you're speaking of another person's father, you use おとうさん

✔ おとうさん、いこうよ！ = Dad, let's go!

       Since you're addressing your own father, you use おとうさん

INCORRECT USAGE (※ Is speaking to someone not in your direct family, like a brother, sister, etc.)

✗ おとうさんは　アメリカに　います。 = My father is in the US.

You will also often hear mothers (and fathers) refer to themselves as おかあさん (and おとうさん) when speaking to their children. 

ANOTHER SUPER IMPORTANT NOTE!!! These words are not supposed to be used when talking about your own family to others according to "proper" (or "prescriptivist") Japanese. However, in casual situations you will often hear people use these words when referring to their own families. It's okay to do so informally. :-)

★ Second, I'll give you the lists of words that are used ONLY when speaking of your own family to others who are outside of your family.

Father = 父　（ちち）

Mother = 母　（はは）

Older brother = 兄　（あに）

Older sister = 姉　（あね）

Grandfather = 祖父　（そふ）
Grandmother = 祖母　（そぼ）


★ Lastly I'll give you the family terms that can be used in either situation!

Younger brother = 弟　（おとうと）
Younger sister = 妹　（いもうと）
Cousin = いとこ
Nephew = 甥　（おい）
Niece = 姪　（めい）

To add "in-law" to the title, place 義理の （ぎりの） before the noun.
Ex: 義理の父 Father-in-law
義理の is also used for "step____" so 義理の父 could also mean step-father depending on the context.