It’s such a simple rule, but few seem to understand it.
If you use an apostrophe, then the phrase, “it is,” must make sense. It doesn’t make sense to say, “The dog is stealing it’s dinner,” because you’d never say, “The dog is stealing it is dinner.”
No apostrophe. “Its” denotes possession, so you’d say, “The dog is stealing its dinner.”
“It’s” means “it is.”
Congrats on getting it right over your brilliant friend.
You could just make it be “Heart on Sleeve”. It may not be grammatically correct, but it sounds better to my ear for that kind of emotional meaning. Sometimes the more grammatically correct, the less emotional it becomes. For instance “The heart is on the sleeve” is the most correct, but it doesn’t evoke much emotion.
It can be confusing to some because the apostrophe normally indicates the possessive case, as in “the dog’s breakfast”. So it’s sort of forgivable to think that “it’s” is a possessive case, rather than the contraction of “it is”. But you’d think that English speakers would figure it out after a while, say, after a lifetime of reading and writing English! I find the misuse of “its” and “it’s” very annoying. I’ll sometimes do it myself, but it’s always the result of a careless typo.
Yes, and it’s not really ungrammatical – it’s a sentence fragment, not a proper sentence, but it’s fine as a slogan.
If you mean a singular heart, then I’d say “heart on sleeve” - by analogy to “hand on heart”, but that’s a matter or preference/style rather than grammar
I suppose. The “it is” rule is infallible, though. That said:
This happens on my laptop, too. Both Word and Google change it wrong. They’ve never fixed their mistake in all these years, so even people trying to get it right hardly stand a chance because they trust these erroneous “corrections”. Makes me nuts.
Good. Best to avoid the whole apostrophe debacle entirely.
I don’t think it’s a simple rule. Sure, you can say that the apostrophe is only right if “it is” would work, but you can also say that the apostrophe is only right if “belonging to it” would work. By the example of nearly every other possessive in English, that looks like it should be valid. “It’s/its” follows one standard pattern, and violates another, and it’s easy to remember that, but there’s no shortcut for remembering which standard pattern is the one it violates.
I understand the point you’re making, but you’ve only demonstrated why you can’t also say that. It doesn’t work. The “it is” rule works every time. It’s a simple way to remember when the apostrophe belongs and when it doesn’t.