2/3用英语怎么说？

two thirds
分子用基数词 分母用序数词加S
分子如果是ONE 分母就不加S

two thirds

分子要用基数 分母用序数词用复数
但分母为1就不要。
还有1/2是a half 1/4是a quarter

two thirds

two out of three
or
two thirds

two thirds

3/4 three fouths

4/5 four fifths

5/6 five sixhs

如此类同，记住后面单词要加s

two in three 、two out of three 、two-thirds