little finger / pinky (noun): this is the smallest finger on the hand. Pinky is an informal name for the little finger.
手上最小的手指。Pinky是小指的非正式稱呼。
例：
He raises his little finger when he drinks a cup of tea.
喝茶時，他總是舉起小手指。
They did a pinky promise to always keep what they did a secret.
他們答應永遠為他們所做的事保密。
A pinky promise is when two people they touch their pinkies or their little fingers together to signify an unbreakable promise has been made. Sometimes it is called pinky swear.
「小指承諾」指的是兩個人互相碰一下小指，表示彼此做出了牢不可破的承諾。有時它被稱為小指宣誓。
ring finger (noun): this is finger that is next to the little finger. It has this name because this is the finger on which a wedding ring is traditionally worn.
在小指旁邊的手指。它之所以叫這個名字，是因為傳統上結婚戒指就是戴在這個手指上的。
例:
He gently slid the engagement ring onto her ring finger.
他輕輕地把訂婚戒指戴在她的無名指上。
middle finger (noun): this is typically the longest finger that is in the middle of the hand between the other fingers.
通常指手中間最長的那一根手指。
例:
I fractured my middle finger while playing football and now it will never be straight.
我踢足球時把中指弄骨折了，現在它再也直不起來了。
It is considered an insult when you only show your middle finger towards someone. And since we are such wonderful human beings we don’t do that type of vulgar thing.
如果你對某人只豎起了中指，這會被認為是一種侮辱。既然我們是如此優秀的人類，我們就不會做那種粗俗的事情。
index finger (noun): The first finger next to your thumb. It is sometimes called the forefinger. You can use the index finger to point, and to press things, to pick your nose… it has so many different uses.
大拇指旁邊的指頭。它有時被稱為forefinger。你可以用食指指東西，按東西，挖鼻子，它有很多用途。
例:
The children had to raise their index finger into the air before they could speak in class.
孩子們必須先將食指舉到空中，然後才能在課堂上講話。
（b不發音）
thumb (noun): the thick digit that is set lower and apart from the four fingers. A thumb is different from a finger in that a thumb only has one joint, while a finger has two joints.
比較低的那個粗粗的收指，它與別的四個手指是分開的。大拇指和手指的不同之處在於大拇指只有一個關節，而其他手指有兩個關節。
例:
Babies often suck their thumbs.
嬰兒經常吮吸拇指。
When you give a thumbs up, it means you approve of something.
當你給出一個向上的大拇指，這意味著你贊成某事。
When you give a thumbs down, it is the opposite and means you do NOT approve of something.
當你給出一個向下的大拇指，相反地，意味著你不贊成某事。