妹って英語でなんて言うの？

The word "sister" is very straightforward in English and there are not many ways to say it other than the two informal ways I listed above.

We use the descriptions above to talk about a sister who is younger than us. 'My younger sister', or if they are very young (a child) we may say 'My little sister' or 'My baby sister'. If you have more than one younger sister, but you are talking about the least old one, then we say 'My youngest sister'.

The two sentences you see provided above are great ways to express to your listener who is your younger sister is. In the second sentence you will notice the word sis. This is a shortened version of the word sister. This is a word that is appropriate for informal settings, like talking with close friends or family.

Although most people will say: my little sister or my baby sister, this could be a little insulting to your sister if she is an adult now. In that case it would be more appropriate to say: "This is my sister who is younger than me". Sometimes people will casually refer to their sister as 'sis', although this would usually only be used among closer friends.

In english, the word "sister" means a female in relation to other daughters of the same parents. "Little sister" means that the sibling is younger than you. Ex: "My little sister is 3 years younger than me, she can be so annoying some times but I still love her." "Baby sister" is another way of saying that your sister is younger than you. In the US, this term is used in a way to be more loving or endearing. It could also be used when referring to a sibling that is actually an infant. Ex: "I am expecting a baby sister in a few months, my mother is 6 months pregnant."