time shifting in WOULD clauses?

On a site on Brazilian-Portuguese lexical differences, I found a sentence on ''prego'':


Brazilian would think that "prego" was a nail. To his surprise, it is a sandwich.



Is shifting of the tenses (IS to WAS) obligatory?
I couldn't say: ''Brazilian would think that ''prego'' IS a nail''?


thanks a lot
hugs

>Is shifting of the tenses (IS to WAS) obligatory?
I couldn't say: "Brazilian [A Brazilian] would think that 'prego' IS a nail?" [Viella]

I don't believe it's obligatory. To me 'is' sounds fine there.

Looking for "would think that" on the net, I come across many examples that have the second verb in the present. Here are the first three Google finds for "would think that":

"I would think that this action is borderline criminal."
"One would think that the more experienced the respondents are...."
"I would think that it is a two[-]way contract...."