Sambahsa has a second person singular different from the second person plural. As in some other European languages, this second person singular is only used when talking to close friends or children. Old English had the pronoun « thou » and the ending « -st ». Likewise, from the same Indo-European source, Sambahsa has the subject pronoun « tu » (pronounce it like « too ») and the ending « -s ».
Say « And you, are you well/OK ? ». « And » is « ed », and don't forget the verb-subject inversion for the question.