as dagmaraka said in polish 'I love you' means <Kocham cie>, but when we write this words we rather use big 'C' so: Kocham Cię or Kocham Ciebie
and I don't know it is right but in:
hungarian: szeretlek
icelandic: Eg elska thig
japanese: Watakushi na anata o aishinasu
suahili: Nakupenda wewe
turkish: Ben sni sviourm
eem .. if there are some mistakes tell me about them