So you're proud because you think you can speak French. But speaking French is nothing. What's really génial is to speak French better than the French. To achieve that life-long goal, you will need to know how to use quelque (one word) and quel que (two words). Space matters.

Try this test. Read the following sentences, and replace the question marks with either quelque or quel que. Compare with the solutions given in the hardlinks. If you fail, go on reading this writeup. If you succeed, then je me demande pourquoi je me fatigue à vous parler en anglais.

??? soit le temps, je veux courir nu dans la rue. Whatever the weather, I want to run naked in the street.

??? stupide que soit l'idée, je veux courir à reculons. No matter how stupid the idea (may be), I want to run backwards.

??? soient, ??? exiguës qu'aient pu paraître, à côté de la somme due, les arrhes... (taken from Mérimée's dictation)

Here are the rules:

quelque is used as an adverb and modifies an adjective, which is followed by que. It is invariable, and means "no matter how + adjective + noun + may be", "as + adjective + as + noun + may be":

Quelque froid que soit le temps, ...
Quelque grandes qu'elles soient, ...

quel in quel que is used as an adjective and it modifies a noun which is the subject of a verb. It is variable (see French Adjective Agreement), and means "whatever", "without regard for":

Quel que soit le temps, ...
Quelles qu'elles soient, ...

After you have decided which one you should use, you should also consider the following usage rules:

  • Both are used with a verb in the subjunctive mood, because they don't describe a fact but an assumption.
  • Only state verbs can be used: "être", "paraître", "sembler", "pouvoir être"...
    Quelque immenses que pussent être mes appréhensions, j'espérais qu'on ne les remarquât point. (I will not even try to translate this ugly example of plus-que-parfait du subjonctif)
  • The subject of the verb is after the verb, unless it's a pronoun. Don't ask why.
  • quelque... que is rarely used in spoken language. I wouldn't even use it in written language, because it's not elegant. Why do I feel it's not elegant? It's hard to answer. Maybe because the sound "q" is repeated three times, and repetition is not elegant in French. Maybe also because the lettre "q" in French sounds like the word "cul", which means "ass(hole)".
  • quel que is commonly used in written or spoken language to insist on something. Politicians love it.

quelque and quel are also used with other meanings in other contexts. For example:

  • quelque may be used as a variable adjective to mean "a few" (plural) or "some kind of" (singular). The second form is not used in spoken language.
    Quelques insectes étaient là. A few insects were there.
    Tu devrais prendre quelque médicament. You should take some kind of medicine.
    Quelque chose. Something. (This one is used in spoken language, and it's very common.)
    Quelques uns. A few people/a few things.
  • quelque may be used as an adjective to mean "around...". Then it's not variable! This form is rarely used in spoken language. But I like it in written language, maybe because it's slightly old-fashioned and I'm proud to be able to distinguish it from the previous form of quelque.
    Quelque 1000 bananes étaient là. Around 1000 bananas were there.
  • quel may be used as a variable adjective to mean "what" or "which". It's used only in questions:
    Quel est le prix d'une banane ? What is the price of a banana?
    Quels sont les policiers qui ont acheté une banane ? Which are the policemen who bought a banana? (I don't translate with "who are...", because I mean: "among these policemen we are talking about, which ones bought a banana?")

Impossible n'est pas français. Simple is not French, either.