Ask the person yes / no questions for answers to questions about their food and comfort preferences using word and gestures like holding up only one item at a time and see if they nod at the item. Their preferences should be honoured when possible.
Their use of language is similar to that of a 2-year-old child. Simple nouns and verb and short instructions such as "Let go", "Wipe your face" are understood. Long sentences and explanations are apt to be ignored.
Their use of language is apt to be limited to immediate experiences with real objects.