Sounds like you found your next promotion at Apple. They can change anything. "I like Pepsi" -> "I like Coke" -> "I recommend Company A" -> "I recommend Company B". etc... "I'm voting for Candidate C" -> "I'm voting for Candidate D"

You can market it is helping people with strong accents to be able make calls and be less likely to be misunderstood. It just happens to "fix" your grammar as well.

Because in regards to the rights to a trademark, what is critical is the use of the word in trade -- not just "marketing material" nor your phone calls to your friends.

So if I write a business email to my colleague, if Apple doesn't autocorrect "Iphone" to "iPhone" in it, they risk losing the trademark?

Your emails aren't very relevant. But the way Apple's represents their product is.