Something I understood very well when taking holidays
with my parents.
All too often there would be some crazy tourist
wandering around the little markets and shops in the town
screaming English words in a French accent. Presumably in an attempt to help the locals understand what he or she was trying to say. It doesn't work.
If what I hear about people who live in tourist-y towns is correct, even fluent English speakers are likely to pretend not to understand you unless you make some effort. Declaring
I'd like two ice-creams. Two. Twooo.
at the top of your voice is unlikely to help.