For what is worth: in Portuguese the adjective comes after the noun so the autocomplete map thingie wouldn't work so well. But I don't think syntax is relevant

For what is worth: in Portuguese the adjective comes after the noun so the autocomplete map thingie wouldn't work so well. But I don't think syntax is relevant to the way most people use search in general and autocomplete in particular. At least from what I can glean from autocomplete suggestions people use mostly keywords, not sentences enclosed by "". So if you type Rio de Janeiro the first autocomplete suggestion is em guerra ("in war", sadly) but none of the other suggestions are well-formed Portuguese phrases, e.g., rio de janeiro turismo isn't a phrase. I might have misunderstood your question, though.