In English, it’s common to see phrases like “a beautiful park”, “an interesting person”, “a big room”, etc. You don’t need to put anything between an adjective and a noun in these cases. In Chinese, things get a bit more complicated. You might need to insert a “de(的)” between an adjective and a noun, depending on what adjective it is. Generally speaking, A “de(的)” is not needed if the adjective only contains one syllable. If an adjective contains two or more syllables, then a “de(的)” needs to be inserted in between the adjective and the noun. Just follow this simple rule and you will be fine. Now let’s have a look at some examples：
English
a beautiful park
Chinese (Pinyin)
yī gè piào liàng de gōng yuán
Chinese (Character)
一个漂亮的公园
(The adjective “piào liàng(漂亮)” contains more than one syllable, so a “de(的)” is needed in this case.)
English
an interesting person
Chinese (Pinyin)
yī gè yǒu qù de rén
Chinese (Character)
一个有趣的人
English
a big room
Chinese (Pinyin)
yī gè dà fáng jiān
Chinese (Character)
一个大房间
(The adjective “dà(大)” only contains one syllable, so a “de(的)” is not needed in this case.)