Mistakes will always be made in French, and now you can learn from them.
Wrong: Tomber en amour
Right: Tomber amoureux
Explanation: Tomber en amour is the literal translation of "to fall in love." The English expression makes love sound like a puddle, or maybe a hole in the ground, that people can fall into and out of. In French, however, love is a state of being, so you "fall loving" rather than "in love."
Je suis tombé amoureux de Françoise !
I've fallen in love with Françoise!