Adjectives
Endings, comparative and superlative
An adjective takes an ending only when it stands BEFORE a noun. After sein, werden or bleiben it stays bare. Das Auto ist neu. no ending ein neues Auto ending Which ending depends on three things at once: the gender of the noun, the case, and whether there is an article in front. That sounds heavy, but two shortcuts carry most of the work: after der/die/das -> mostly -e, and -en everywhere in dative and plural after ein/kein/mein -> the adjective supplies the gender signal itself
Persian adjectives never change — «ماشین نو», «خانهٔ نو», «کتابهای نو» all use the same word, joined by an ezafe. German changes the adjective itself, and the change depends on grammar you cannot hear in Persian at all. Good news: the ending is almost always -e or -en. Learn to reach for -en whenever you are in the dative or the plural, and you will be right most of the time.