All three versions occur, though they don't falute the same.

• (c) is the canonic source, with simple Wh-fronting, leaving is at the end of the sentence:

does anyone know [the task for the afternoon is what]? ==>

does anyone know [what the task for the afternoon is]?

• (b) is a further variation on (c), with the prepositional phrase for the afternoon, which modifies task, moved (by the rule of "Extraposition from NP") from right after task to the end of the sentence.

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what the task is for the afternoon]?

In this position, it balances the is. This is an esthetic improvement, not a grammatical one. English doesn't like long complex sentences that end with is (like (c) -- the effect is rather like hearing the first two musical notes of a 3-note chord progression; you keep waiting for the other note to drop.

• (a), on the other hand, is a variant of (c) with Subject/Auxiliary Inversion performed, the same way it would be on a real, non-embedded, information-seeking question. It's not proper written English, but is very common in speech, where it has an additional pragmatic usage to signal that the speaker really does want an answer to the question, and not just a Yes or No. (Notice, by the way, that this also has the effect of keeping the is away from the end of the sentence, which is another reason it occurs so frequently.)

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what is the task for the afternoon]? (Tell me, please; I really need to know)

All three versions occur, though they don't falute the same.

• (c) is the canonic source, with simple Wh-fronting, leaving is at the end of the sentence:

does anyone know [the task for the afternoon is what]? ==>

does anyone know [what the task for the afternoon is]?

• (b) is a further variation on (c), with the prepositional phrase for the afternoon, which modifies task, moved (by the rule of "Extraposition from NP") from right after task to the end of the sentence.

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what the task is for the afternoon]?

In this position, it balances the is. This is an esthetic improvement, not a grammatical one. English doesn't like long complex sentences that end with is (like (c) -- the effect is rather like hearing the first two musical notes of a 3-note chord progression; you keep waiting for the other note to drop.

• (a), on the other hand, is a variant of (c) with Subject/Auxiliary Inversion performed, the same way it would be on a real, non-embedded, information-seeking question. It's not proper written English, but is very common in speech, where it has an additional pragmatic usage to signal that the speaker really does want an answer to the question, and not just a Yes or No. (Notice, by the way, that this also has the effect of keeping the is away from the end of the sentence, which is another reason it occurs so frequently.)

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what is the task for the afternoon]? (Tell me, please; I really need to know)

All three versions occur, though they don't falute the same.

• (c) is the canonic source, with simple Wh-fronting, leaving is at the end of the sentence:

does anyone know [the task for the afternoon is what]? ==>

does anyone know [what the task for the afternoon is]?

• (b) is a further variation on (c), with the prepositional phrase for the afternoon that modifies task moved (by the rule of "Extraposition from NP") to the end of the sentence.

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what the task is for the afternoon]?

In this position, it balances the is. This is an esthetic improvement, not a grammatical one. English doesn't like long complex sentences that end with is -- the effect is rather like hearing the first two musical notes of a 3-note chord progression; you keep waiting for the other note to drop.

• (a), on the other hand, is a variant of (c) with Subject/Auxiliary Inversion performed, the same way it would be on a real, non-embedded, information-seeking question. It's not proper written English, but is very common in speech, where it has an additional pragmatic usage to signal that the speaker really does want an answer to the question, and not just a Yes or No. (Notice, by the way, that this also has the effect of keeping the is away from the end of the sentence, which is another reason it occurs so frequently.)

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what is the task for the afternoon]? (Tell me, please; I really need to know)

All three versions occur, though they don't falute the same.

• (c) is the canonic source, with simple Wh-fronting, leaving is at the end of the sentence:

does anyone know [the task for the afternoon is what]? ==>

does anyone know [what the task for the afternoon is]?

• (b) is a further variation on (c), with the prepositional phrase for the afternoon, which modifies task, moved (by the rule of "Extraposition from NP") from right after task to the end of the sentence.

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what the task is for the afternoon]?

In this position, it balances the is. This is an esthetic improvement, not a grammatical one. English doesn't like long complex sentences that end with is (like (c) -- the effect is rather like hearing the first two musical notes of a 3-note chord progression; you keep waiting for the other note to drop.

• (a), on the other hand, is a variant of (c) with Subject/Auxiliary Inversion performed, the same way it would be on a real, non-embedded, information-seeking question. It's not proper written English, but is very common in speech, where it has an additional pragmatic usage to signal that the speaker really does want an answer to the question, and not just a Yes or No. (Notice, by the way, that this also has the effect of keeping the is away from the end of the sentence, which is another reason it occurs so frequently.)

does anyone know [what the task for the afternoon is]? ==>

does anyone know [what is the task for the afternoon]? (Tell me, please; I really need to know)