1、both 意思是“两个都”，可作主语，宾语或同位语等，常与and 连用，连接两个并列成分，作主语时谓语动词用复数。
2、both of 后跟名词/代词复数 ，可作主语，宾语；作主语时谓语动词用复数。
1、She cried out in fear and flung both arms up to protect her face
2、Now women work both before and after having their children
3、Put both vegetables into a bowl and crush with a potato masher.
4、Any such action would have to be approved by both American and Saudi leaders.
1、We were both of the same nationality.
2、Both of the wrestlers tried to tumble the adversary with all their strength.
3、Both of these dancers knew full well why they attracted the attentions of two hot-blooded young men.
4、Both of my sisters moved even farther away from home