koi - sharp
Ko wai ngā tamariki koi ngā hinengaro?Who are the children with sharp minds?Asking who - Ko wai...?
He koi te arero.The tongue is sharp.
He kamakama te hinengaro, he koi hoki te arero.She is quick-witted, and also sharp-tongued.
He koi ia.He is sharp.
Kia tūpato, he koi tēnā oka.Be careful, that knife's sharp.