BBC trots out a dependable warhorse: a menu of "bad grammar" (link). We can look forward to the dependable followup warhorse: a shouting match over which of these are really "bad."
Okay, I'll take the bait. I admit I am not bothered by "for free" (v. "for nothing"), or "on foot" (for "by foot"), or even "stadiums" (for "stadia"). "I" for "me" may betray a certain shakiness in structure, but it rarely obscures meaning. My recollection is that in some foreign language classes, I even learned names for certain items of "bad grammar"--think "accusative by attraction"--and if it has a name, I guess it has a place at the grownup table.
But some solecisms trench upon useful distinctions that should be maintained. "Fewer" v. "less:" it may matter whether we are talking about number or volume. "Affect" v. "effect"--now, those really are different, and I would keep it so.
I admit to being a bit ticky-y myself about some things. I bend every effort to not split an infinitive (tee hee), even though I know we do it only in a misguided imitation of unsplittable Latin. I'm pretty careful about saying "none is" rather than "none are"--and I am amused tht there is a good argument that my reasoning is misguided, and that in any event, the plural form has been around since the time of King Alfred.
But what about "anyone else's"--in a grammatically pure world, shouldn't it be "anyone's else"--and have you ever heard anybody actually say "anyone's else"--?