請問什麼時候該用other,什麼時候該用another ?

another : 另一 / 又一  (只可接上單數名詞)
================eg. He drank a glass of beer and would like to have ANOTHER glass.他喝了一杯啤酒 and would like to have 另一杯.

other : 其他的；別的
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a) 通常接上眾數名詞 
eg. He drank a glass of beer and would like to try OTHER drinks.
他喝了一杯啤酒 and would like to 再試 "其他的"飲品. 

b) 但在以下的 "情況/用法", 則接上單數名詞 :
1. the other one 另一個
eg. l don't like this bag. l prefer the other one. (一共只有 2 bags) 

2.另一邊的
eg. . . . on the other side of the street. . . . 在街的另一邊 (一條街只有 2邊)

3.別的
eg. Don't look at other people. 不要看別人 

other ，沒有指明，或有很多，another 或者an other有指定那一個