"Whenever" and "Seen"

[Jessika]

The one that really bugs me, that I see everywhere these days: people using "it's" when they mean "its."

it's = contraction of "it is"
its = possessive of "it"

I'll even have trouble remembering this one because the apostrophe is "backwards" (in my mind, anyway lol). Normally you use the apostrophe to show possession but not in this case. You'd think I would keep that straight, knowing that... but, nope.