fourteen

The project will be completed in fourteen days.

(Chinese) 这个项目将在十四天内完成。

Valentine's Day is celebrated on the fourteenth of February.

(Chinese) 情人节在二月十四日庆祝。

He learned to play the guitar when he was fourteen.

(Chinese) 他十四岁时学会了弹吉他。

In many school systems, students enter high school at age fourteen.

(Chinese) 在许多学校体系中，学生十四岁进入高中。