1. 属正式用词,主要用于肯定句或疑问句,一般不用于否定句 (否定句可用 either),它在句中通常放在实义动词之前,特殊动词 (动词be、情态动词、助动词)之后,有时也放在整个谓语前面或放在句首或句尾 (较少见,且多半是因为强调之故)。如:I’ve also read the book. 我也读过这本书。This room was also dirty. This room alsowas dirty. This room was dirty also.
Also this room wasdirty. 这个房间也很脏。

 2. 有时由于 also 位置不同,可能会导致句子含义不同。如:We alsoregard him as a great writer today. 我们也 (同别人一样)把他看成当今伟大的作家。We regard also him as a great writertoday. 我们把他 (We regard also him as a great writertoday. 也看成当今伟大的作家。
We regardhim as a great writer also today. 我们仍 (同其它时候一样)把他看成当今伟大的作家。

 3. 在简略答语中,习惯上不用, 如一般不说 I also, 但可说Metoo, You too等之类的。如:A:I’m tired. 我累了。B:Me too. 我也是。
B:I also. (误)