No, that is not wrong and it is not the same. You are not the French language, but when you speak French or write in French, then we are talking about the French language and it is a masculine noun. You are French, as in nationality or culture. This is an adjective which must match the person or thing that is being described. So, it is "Je suis française.", but "Je parle français."
Hi saksxalmo, You need to say what kind of question you were answering; the same phrase will be used again and again in different types of question. If you were asked to translate "I am French", then you're right, if you were asked to listen to "Je suis francais", then writing "Je suis française" would not be accepted because the difference should be audible.
The writer, not the reader of the sentence, is the person who happens to be feminine when the word "française" is used and "français" in this sentence would be for a masculine author. Now be careful, for the language is "le français" which is always masculine. All nouns in French are either masculine or feminine and adjectives must match the gender (masculine or feminine) as well as the number (singular or plural) of each noun.
le vin français = the French wine
la voiture française = the French car
You can always kook up a noun in a dictionary to find its gender. https://dictionary.reverso.net/english-french/car
It is the conjugation of the verb specifically for "je".
"je suis" = " I am"
"tu es" (familiar singular) = "thou art" but it is still used in French, so in English it is now "you are"
"il est" = "he is"; "elle est" = "she is"
"nous sommes" = "we are"
"vous êtes" (plural or formal singular)= "you are"
"ils sont" or "elles sont" (for all female group) = "they are"
je suis = I am
tu es = you are or thou art
il est = he is; elle est = she is (There is no "it" in French. Every noun is either masculine or feminine, even things.
nous sommes = we are
vous êtes = you are (plural or formal singular or formal plural)
ils sont = they are (at least one male in the group, so coed or all male)
elles sont = they are ( all female group)