When you have various adjectives before a noun you use a hyphen when the first adjective defines the second adjective rather than the noun.

eg. a long boring phone call (no hyphen because long qualifies phone call as does boring.

BUT-
a long-awaited phone call

long here qualifies awaited rather than phone call
Hope this helps you

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Note added at 2002-03-20 13:22:40 (GMT)
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I\'ve realised I haven\'t really helped you with your question. I think you\'re right in \'highly sought-after product\'
highly is an adverb and qualifies sought-after and normally adverbs don\'t need hyphen
a beautifully made bag.
seek after is a phrasal verb and when these are used as nouns or qualifying adjectives/participles they often take a hyphen


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Note added at 2002-03-20 18:33:20 (GMT)
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I correct my sentence, seek after is not a phrasal verb but the logic is the same when a verb and its dependent participle are functioning as a qualifier before a noun :-)

Sylvie,

The above answers are perfect: highly sought-after ...

I just wanted to confirm that this is perfectly alright for the Canadian market as well.

Sought-after is a derivative (Participle II) from the verb "to seek after".

This combination is called in grammar a verb collocation: A combination of a verb and a preposition where the preposition cannot be dropped without changing (sometimes drastically) the meaning of the remaining verb.

Examples:

To give - self-explanatory;
To give IN
To give UP - totally different meanings.

These are verb collocations.

English is a language where verb collocations is a very popular means of word-formation.

In this respect I would distinguish "long-awaited" from "sought-after" in terms of how they were formed.

Although "to seek" and "to seek after" are synonyms differing only in degree of desire to get something (and in frequency/ compatibility of usage), the expression "to seek after" is still an indivisible verb collocation (not such a bright version as "give in", "give up" etc., though).

So when it's used as a derivative, in this context as a Participle II serving in the sentence as an attribute, it should be presented in a sort of "togetherness" which is attained through hyphenation.

That's why it's grammatically illogical to put hyphenation any place else other than between the members of the original collocation from which the derivative has sprung.

. . . I believe the question you may want to consider is not where to put the hyphen (I know you would not put it after "highly"), but rather whether a hyphen is called for between "sought" and after, and under what circumstances.

You would not put a hyphen after "highly" because simple adverbs feel quite comfortable sitting next to the adjectives they qualify without any hyphenation, thank you: a highly motivated worker, a highly recommended diet, a highly endorsed candidate, etc.

So why put a hyphen between "sought" and "after"?

The two words by themselves do not always require a hyphen. It is the use of the phrase "sought after" as an adjective qualifying a noun that calls for the hyphen. To illustrate what I mean, consider the following example:

"These cashmere vests are highly sought after."

In this case, no hyphen is called for. Here, the adjective "sought after" serves as a sentence complement. Parallel sentences:

- This proposal needs to be carefully looked at.

- This house has been broken into.

- The bishop has been spoken to regarding the annulment.

etc.

When, however, the adjective "sought after" serves to modify an explicit noun, you need the hyphen for a very practical reason, namely to make sure that the reader construes "after" as part of the phrase "sought after," and not as a preposition aimed at the noun that follows:

- These are highly sought-after sweaters.

Here, "sought after" is one unit. The hyphen helps maintain that logic.

Fuad