"Jose, the confusion for ESL students, I imagine, is because "used to" is pronounced exactly as if it were "use to". The 'd' sound vanishes. There is a subtle difference in the way the remaining word is pronounced, which together with context is sufficient for a native-speaking listener." 

Indeed Pat, this is one point the fact that /d/ vanishes in native speech and another one and, that's my guess, is that in Portuguese when you want to emphasise present or past habits you can use the verb costumar a (estudar/cantar/ler...) and an ESL Brazilian student normally deduces from used to that there might be a present form for this structur,  as we have in Brazilian Portuguese.

Marry Christmas.

JR