Ein super Restaurant

My wife is learning German, and she asked me if she could say "ein super Restaurant". It certainly sounded like something I might hear from a native speaker, and a Google search confirmed that it is common enough. But how can it be grammatical? If "super" is an adjective, then surely it should be "ein superes Restaurant"? I know that foreign adjectives that end in a vowel (e.g. "lila") are not declined like native adjectives, but I thought that if they end in a consonant then they are declined ("ein cooles Restaurant"). Am I wrong about this? Or is "super" a special case?

Super seems to be a special case, but don't ask me why...
It doesn't behave like other adjectives, not only in that it doesn't seem to agree with the nouns it describes, but also in that it doesn't have comparative and superlative form, unlike cool: cool, cooler, das coolste Restaurant - not something I would usual write, but quite acceptable in spoken German. But never super, superer, das superste.

If I find the time, I'll try to find out more about it, but but the moment all I can tell you is that your wife would be quite right to say "ein super Restaurant".

I don't speak German. But, I keep hearing super, pronounced 'zoopah', all the time from Germans.
And it doesn't look like the usage of the word is subject to any linguistic rules of German grammar. It's just like implanted word in one form, 'super'.

#1, "sexy" is another one of those words too, I wonder? Eine sexy Frau, for example?

orangutan, "sexy" ends in a vowel.

Is that the rule?

orangutan, did you read my OP?

No, sorry, I don't read. Ich verstehe nur Bahnhof.

Oh, you meant when the sound of a foregin adjective words ends with a vowel,not the word itself. Right....

Get a grip, orangutan! This is Speaking in Tongues, not Sister Patricia's Spelling Bee. "Sexy" ends with a vowel.

Wow, du sprichst so viele Sprachen! Sehr beeindrueckend!!

Where did that come from?

It has nothing to do with what letter the adjective ends. "Super" is an adjective of foreign origin and it is non-declinational. Other examples are "extra" or "prima". As often there are exceptions as well and "cool" is such an adjective. There are also German adjectives that are non-declinational, e.g. "weniger".

I had second thoughts about those foreign adjectives. Could it be that there is a distinction depending on syllables? Maybe short worts with only one syllable do change while words with two or more syllables do not? This would explain the difference between super and cool. Just guessing here and trying to think of other examples but nothing comes to my mind right now.

Cosmopolitan, no, it does not have something to do with syllables. And "weniger" is declinable:
wenig, weniger, am wenigsten; ein paar wenige Euros; nur wenig Geld....

super is indeed special, it is just used in this form. German is quite complicated, we do have a lot of exeptions. It is just like the irregular verbs in English, you need to remember them...

I realize that syllables do not trigger declination. After some more thinking "top" came to my mind and it only has one syllable but is non-declinational.

I am not too sure about "weniger" because I was not referring to the positive, comparative and superlative. The comparative "weniger" itself is non-declinational - at least I cannot think of an exception.

No, of course the comparative weniger is not declinable, but I gave you two examples which show thet the word "wenig" is...

cocolino18: "of course the comparative weniger is not declinable". OK, but why? Comparitives usually decline. So what's this "of course"?

Cosmopolitan #11, "extra" and "prima" end in vowels. So naturally they don't decline -- they can't. It looks like you didn't read my OP either!
But "top" is a good example of the "super" phenomenon.

Two observations:
> - Top as in " ein top Hotel" certainly exists. BUT the declined version "ein toppes Hotel", in which the world feels much more adjectivy to me, is not as impossible as "eine superes Hotel".

• While super ends in a consonant in the written form, the sound it ends with is actually a vowel, not unlike the a in prima and extra.

I know there are German adjectives ending in the same sound which decline perfectly well (ein leckeres Bier), but they are not foreign. Could this be some kind of explanation? Foreign adjectives that end in a vowel SOUND do not decline like native adjectives.

Mmh, I'm sure someone will come up with an example that will prove this wrong as well.

Oh, and by the way, people do actually try to decline adjectives like lila - "eine lila(n)e Hose", just like "ein rosanes Haus", the latter being quite acceptable. Does not work for prima and super, though.

I think it is just one of the many exceptions one has to learn by heart to get it right.

Cosmopolitan #20, that is an admission of failure! Also, what do you mean by "it"? Do you mean "super", or "eine lila(n)e Hose", or what?