Swedish has two indefinite articles for singular nouns: en and ett. Therefore all the nouns are categorized in these two groups. How to know if your favourite noun is en or ett? The answer is simple! Norstedts ordbok or SAOL. Even though there are few possibilities to guess (t.ex. Living beings and nouns ending with -ng are usually en nouns) the best and probably the easiest way is to remember article together with a noun. That makes life considerably easy, giving the fact that ending of the adjectives depends on en/ett form of the noun. Try this: en bil, en fin bil. Ett bord, ett fint bord.