As in many Asian cultures, language is rarely used in an absolutely literal fashion. Much of what is actually meant can be hidden behind a smoke screen of vagueness and coded language. It is impolite and disrespectful to disagree openly and therefore anything other than an unequivocal 'yes' should be viewed with some wariness. Probe for further information, go back to the subject later in the meeting and use flip charts, diagrams etc. to aid mutual comprehension.