Meaning & Definition of Reword in English

When an English speaker realises that a foreign person they are speaking to doesn't understand one of their sentences, they repeat it, the same way, but louder, as though the person were deaf. At no point does it come to their mind that their vocabulary might be complicated or that their expression might most probably be ambiguous to a foreigner and that they could reword it in a simpler way. The result is that not only the person still doesn't understand, but gets irritated at being considered deaf.