the fourth one is mine.意思是第四個是我的。fourth是序數詞，意思是第四的，第四。常做定語。例如the fourth monkey第四隻猴子。它一般不單獨使用，與the及名詞搭配使用。若要單獨使用時，用在排列的場合：一般陳述觀佔時，first， second， third， fourth…並列使用。
fourth的造句如下
1、
He is beginning his fourth consecutive term of office.
他開始了第四屆任期。
2、
This was the fourth album by the top rock outfit.
這是這個頂級搖滾樂隊的第四張唱片專輯。
3、
The 800 metres is the fourth event of the afternoon.
800米賽是下午的第四項比賽。
1、He himself bad only finished the fourth grade.
They hit pay dirt on the fourth day.
