Predictive Text

Hi this is a very minor thing really, but when I type in the first few letters of a Supplier name when I'm creating a new supplier bill, a predictive text thingie changes it to a proper word, so then I have to delete and start again. How do I switch off the predictive text thingie or set it to search the supplier list using the actual letters I typed in, rather than what it thinks I'm trying to type? because it's driving me nuts!

Thank you!

Amanda