“Is when”, “is where” and similar constructions are wrong.
Everyday, I hear such phrases being used on national news, in press meetings by heads of state, and from other people who you think would know simple grammar.
To me, it stands out as much as someone saying “I were sleeping” or something absolutely ridiculous.
How can people for whom English is a first language not know simple grammaratical rules?
Studi
An example, so I follow you correctly:
“Something I can’t stand is when people use improper grammar.”
I’m sorry, but English is my first language, and I’m not sure how to properly phrase that if “is when” is an improper construction. Enlighten me, please? Should it instead be, “Something I can’t stand: People using improper grammer.”
Not trying to be a smart-ass, just honestly not sure if the latter example is the proper way. And what is so improper about “is when” or “is where”?
If such constructions are in such common use, doesn’t that pretty much them correct by definition?
Should English books describe the language as it is used, or are we to change the use of the language to adhere to the English books?
The “is when” and “is where” constructions seem perfectly clear and unambiguous. Why not use them?
“My car is where I left it”…?
Err, I suppose you could say, “my car is in the space where I left it”, but I’m not sure that really changes anything.
Fuck it; it doesn’t sound so damn wrong to me.
I wish…I wish…I wish I were a gopher…
(I were can be correct, leftover usage of subjunctive).
Stupid grammar.
Shouldn’t that say grammatical?
I speculate that Studi does intend constructions of the sort illustrated by Crunchy Frog’s example. A less exceptionable sentence might be:
Something I can’t stand is people using improper grammar.
Some serious pedants might prefer:
Something I can’t stand is people’s using improper grammar.
(But not this serious pedant!)
I agree that Studi has not presented the details of the objection pellucidly.
Probably the same way I can’t spell “grammatical”. (Excuse my sentence fragment.)
A correct form would be “Something I can’t stand are the times when people use improper grammar.”
The easiest way to fix an “is when” error is simply to insert “the time” between “is” and “when”. Inserting “the place” usually works for “is where” errors.
It becomes obvious that “is when”, “was where” etc., are wrong when the offending sentence is analysed. “Is” can be followed by something like an object, or subjective completion, or a noun clause. Something like “when people use improper grammar” could be a subordinate adjective clause, but this requires a noun as an antecedent.
Studi
That first sentence should read “doesn’t that pretty much make them correct by definition?”
Sorry, Studi. Your sentence
Something I can’t stand are the times when people use improper grammar.
is a mess! Something must be singular, so it must take the singular form of the verb: is; and then it is very odd to follow this with the times.
It may be technically “faulty” (my 1972 Holt Guide to English calls it “awkward”), but it’s in common usage nevertheless.
http://occ.awlonline.com/bookbind/pubbooks/aaronlbh_awl/medialib/usage/gloss_09.html
I must disagree with the OP.
The most common grammatical error’s involve folk’s using apostrophe’s where they are unneeded, unwanted, and serve to drive honest, upright, intelligent people STARK RAVING MAD.
Plural usage demand’s that you stop inserting punctuation mark’s in the wrong place’s, merely because you have no clue’s about how to communicate and want to stick in apostrophe’s on the off-chance that they are necessary, so that you don’t look like a dumbas’s.
Well, you do.
Jiveass twits.
Nope. “Something” is the subject of the sentence and “when people use improper grammar” is the predicate object. The entire phrase is the predicate object. Since the subject, “something,” is singular, the verb is singular also.
Slang, studi, slang. There’s a difference between the “your/you’re” error and the clipping of grammar rules for the sake of brevity… especially when that shortcut is almost universally understood and accepted.
OW OW OW
Brain hurts!
That’s just “Phantom Pain”, Kelli. 
I have been bitchslapping people for bad grammar for years, and I have never heard this rule.
It ain’t bad, its just a different grammaratical strategery.
I’ve never come across this as faulty grammar, either, and I’ve been studying grammar mixups for a while now. People know what you mean when you say it, and everybody uses it, so it’s acceptable. As has been said before, it’s a shortcut. Revising the sentence to avoid using those phrases would make it rather unwieldy in most cases. The only people who would insist on avoiding it are major pedants, who in my oh-so-humble opinion would only trot out the rule to make themselves look superior. I suspect modern linguists would just giggle at this being called bad grammar. Sigh. Maybe I should change my major from Business to Linguistics, it’d be so fun to have some authority in this area. 
[sub]Man, I still wish I had The Language Instinct. Stephen Pinker’s awesome.[/sub]
Even looking in books which are prescriptive instead of descriptive, I can’t find anyone with their knickers in a knot over this one.
Studi, can you find an actual citation of some authority saying this is wrong? None of my references even mention it let alone correct it.
Dude.