それにもっと水をたしなさい。

besides; in addition; also; moreover

(some) more; even more; longer; further

water (esp. cool, fresh water, e.g. drinking water); fluid (esp. in an animal tissue); liquid; flood; floodwaters; water offered to wrestlers just prior to a bout; break granted to wrestlers engaged in a prolonged bout

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to take out; to get out; to put out; to reveal; to show; to submit (e.g. thesis); to turn in; to publish; to make public; to send (e.g. letter); to produce (a sound); to start (fire); to serve (food); to begin ...; to start to ...; to burst into ...

to do