Apostrophe

[scripto]

1.) Each others shoes.
Does others have an apostrophe? Is it before or after the s?

2.) Bird's down in a nest.
Does birds have the apostrophe before or after the s?
(Birdsdown? Bird down?)

3.) In four day's/days' time?

[MikeNewYork]

1.) Each others shoes.
Does others have an apostrophe? Is it before or after the s?

2.) Bird's down in a nest.
Does birds have the apostrophe before or after the s?
(Birdsdown? Bird down?)

3.) In four day's/days' time?

1. other's (singular possessive)
2. birds (plural)
3. days' (plural possessive)