What is the difference between 早い and 速い??

Because conjugations!

早い is a い-adjective, meaning that you need to conjugate it based on what you do with it. If attatching it to a noun, then you can leave it as it is... see example below. 早い車- Fast car

Now if we attatch it to a verb, we need to change the final い to a く. An a example below. 早く走る- run quickly.

Negatives for い-adjectives are based off of ない (negative ある). Because that is a verb (of sorts), we change it first to the adverb form (早い to 早く) and stick on the ない, like in the question. 早くない (not quick)

Past tense of い-adjectives take on かった in place of い. 早い to 早かった. (was quick)

ない is also treated as an い-adjective, so past negative would be... you guessed it! 早くなかった (wasn't quick)

i think replacing the "い" with "く ない" makes it negative?

早い is an い-adjective, adjectives in Japanese have their own conjugations just as verbs do. In this case, the negative conjugation of the い-adjective is to drop the い at the end and replacing it with くない, thus it turns into 早くない.

Yes . Have the same question

When you are negating a ｓｔａｔｅｍｅｎｔ

Six months later 彼女 is not accepted, which perplexes me as it has been accepted in earlier lessons without a problem.

According to my dictionary, 早い and 速い refer to the same word but 早い is the more used kanji. That might be why 速い is not accepted... but I might be wrong with why Duolingo rejects it.

nai is a suffix not a separate word

It wants an explicit "she", and fast is 早い (hayai) not あやい (ayai).

Because it is はやく to start and not あやく.

No, this is the standard formal form. The informal would omit the です.

• 早い = early
• 速い = fast

Other than different kanji, nothing much as they refer to the same word according to my dictionary. 早い is more commonly used over 速い for the adjective はやい.

its always ません or くない. you cant mix the two up

If you want to use ませんthen you can say はやくじゃありません(hayaku jya arimasen)

thanks guys!