Text messaging

[CalamityK2]

Why is it that when using predictive text, the stupid phone often finds it impossible to identify a word like "daft", but offers such gems as Dadu, dadt, dadv and dad8 - none of which, as far as my dictionary is concerned, are proper words? I mean, fair enough if it hasn't heard of a word (I accept that it can't have heard of ALL of them) but what's with the gibberish alternatives??