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.