Answer:
Well, you could try Googling "translate into (insert language here)" to find online translators, if you only need to know in a few languages.
Or, consult this website to find out how to say "I love you" in lots of different languages. http://www.galactic-guide.com/articles/2R95.html
To get you started, here are a few translations:
Afrikaans -- liefde
French -- amour
Hebrew -- ahava
Italian -- amore