Wǒ duì nǐ yíjiànzhōnɡqínɡ.

我对你一见钟情。

I fell in love with you at first sight.

Notes:

我(wǒ): I

对(duì): to

你(nǐ): you

一见钟情(yíjiànzhōnɡqínɡ): fall in love at first sight

Example:

A：我对你一见钟情。

     Wǒ duì nǐ yíjiànzhōnɡqínɡ.

     I fell in love with you at first sight.

B：我没有。

     Wǒ méiyǒu.

     I didn’t.