une région française intéressante.
Mistake: Missing the uppercase at the start.
Correction: Une région française intéressante.
En automne les couleurs sont fantastiques: rouges, bruns et jaunes.
Mistakes 1: Missing space before the colon (deux points).
It's not really a grammatical error, more a typo rule. In French all "dual signs" have a space before and after.
end. Start (point is single punctuation sign, no space before, a space after)
This, that (coma is single sign, no space before, a space after)
This ; that (double punctuation sign, space before, space after, uppercase after)
This : that
The parenthesis have spaces outide, no space inside
This is (an exemple) of parenthesis.
Mistake 2: "couleurs" is feminine plural, it should be "brunes".
Though, "brun" is not often used to specify a color, it's reserved for hair and animal fur.
Je suis brun = J'ai les cheveux brun (I'm brun = (subjective that we are speaking about the hairs, because "brun" is for hairs or fur) = I have brun hair color).
Un ours brun (instead of marron, because it's the fur's color of the bear).
for autumns, you should use "marron" instead.
Correction: En automne les couleurs sont fantastiques : rouges, marron et jaunes.
Note: Marron is invariable !
No feminine, no plural.
Grammatical rules for colors:
Colors are a little difficult in French.
The rule is : these are adjectives, they are accorded with the object they define in genre (masculine/feminine) and nombre (singular or plural).
There is a rule exception for word accord: everything that exists as another object's name is invariable. For example:
marron (marron color) is a fruit, citron (yellow color) is a fruit, orange (orange color) is a fruit, caramel (marron color) is a candy, abricot (orange color) is a fruit, ardoise (grey color) is a stone type, etc.
But that rule's exception itself also has an exception (double exception!): colors from object's names but which are not invariable: mauve, pourpre, rose, écarlate, fauve, vermeil et incarnat. (these ones need to be accorded)
Examples:
Des oranges orange (haha, first is the fruit, second is the color)
Des citrons verts (citrons is the fruit, so it's plural)
Des feuilles marron (marron here is the color not the fruit, so it's invariable)
Des chaussettes roses (rose is the color, it's also a plant but is part of the "double" exception list so it needs the plural form)
Des roses jaunes, des roses blanches.
The only "double exception" that you might encounter are: rose (rose color) and mauve (violet color).
The other names are rare, so if you need to remember the double exception list, just remember "rose" as it's the only one which is a plant and is easy to remember.
"everything which is an object/plant/etc. is invariable, except rose"
Vichy est une grande et riche ville.
That one is fine.
This form is not used on oral conversation (dual adjectives), but is grammatically correct.
For information only, oral speaking we would have said : grande ville riche.
Some adjectives can be placed after the word, some can't.
You can't say "Une ville grande.", you need to say "Une grande ville."
but you can say either "Une riche ville." or "Une ville riche."
You can't say "Une rouge pomme." but "Une pomme rouge."
I don't know if there are a rule for that, it might be the use which determine which "looks" better to hear.
someone can help here?