Did you know that using accented characters in Google AdWords would mean you need to use both variations? For example, if you advertiser for the keyword [construção], you would also need to advertise for the unaccented version [construcao]. I guess this is a good thing, because sometimes, advertisers only want to show their ads to those who are capable or knowledgeable to use accented characters when searching.

A Google AdWords Help Discussion asks this question. AdWordsPro Sarah replied saying:

So technically, they are different words. But if you use broad match, it is possible, but not guaranteed, that Google will show your ad when you bid for [construção] but someone searches for the unaccented version of [construcao] or visa versa.

We discussed a similar topic two years ago on how the non-paid algorithms handle accented characters.

Forum discussion at Google AdWords Help.