Question

在某人二十多岁的时候的英语表达中,in one's 20's和in one's 20s哪个对,还是两个都对?

Answer 1

一般来说是 20s，但也有说美英 20's，英英用20s

In British usage, we do not use an apostrophe in pluralizing dates:

This research was carried out in the 1970s.

American usage, however, does put an apostrophe here:

This research was carried out in the 1970's.

其他来源的解释：

The Chicago Manual of Style recommends no apostrophe is something like 1960s.

Ages are the same kind of thing. Consequently, the better form is:

This is her brother WILLIAM (30s), fat, poorly dressed.

所以最好不加撇号（apostrophe ），用20s