I try to use words I think a model whom speaks another language would understand. I have personal pet peeve with redundancy in speaking, so I try to use words I feel provide more of a variety in English.
When I speak to models who are second or third language English speakers, I have to consciously try to use simpler vocabulary.
However... I have also been piqued into learning Romanian, so it is always fun to learn from the models, and teach them at the same time.