tā koutou - your (singular, addressed to three or more people)
He aha tā koutou mahi inanahi nei?What did you guys (3+) get up to yesterday?What are you doing? - He aha tāu mahi?
He aha tā koutou mahi i te kura i tēnei rā?What did you guys get up to at school today?What are you doing? - He aha tāu mahi?
He aha tā koutou mahi i te marae i te Rāhoroi?What were you guys doing at the marae on Saturday?What are you doing? - He aha tāu mahi?