In Japanese, there are different terms used to name members of your own family versus someone else’s family. There may also be two ways to call members of your own family depending on whether the situation is formal or informal. Let’s take a look:

Father (own family in formal situation) – ちち (父)

Father (own family in informal situation) – (お)とうさん also パパ will work as well

Father (someone else’s family) – おとうさん (お父さん)

Mother (own family in formal situation) – はは (母)

Mother (own family in informal situation) – (お)かあさん or ママ

Mother (someone else’s family) – おかあさん

Grandfather (own family formal) – そふ (祖父)

Grandfather (own family informal) – おじいさん

Grandfather (someone else) – おじいさん

Grandmother (own family formal) – そぼ (祖母)

Grandmother (own family informal) – おばあさん

Grandmother (someone else) – おばあさん

This isn’t a definitive list of the terms used for family members. Stay tuned for the rest in the next post. What I hope you’ve realized is the pattern used for the various names used to call your own family versus those used to call someone else’s family. For someone else’s family, the suffix さん is always attached. In a standard Japanese language class you’ll probably learn that mother and father is おかあさん and おとうさん in an informal situation. However in reality, some people leave out the honorific prefix お when they address their own parents. This is especially true for children.