Up to 1 minute
Water is conjured directly into the lungs of a targeted creature that you can see, as long as the creature has lungs and is not undead or a construct. The creature immediately begins suffocating, and cannot speak, and has disadvantage on Attack rolls and Abil. Checks. The creature remains conscious and in this state for a number of rounds equal to its Con modifier (min 1 round).
At the beginning of the target's turn each round, the target must make a Con saving throw. When successful, the creature uses their action to cough up water and the spell ends. Another creature can attempt a Wis (Medicine) check as an action to clear the water from the target's lungs, DC equal to your spell save DC.
Once the target has been affected for rounds equal to its Con modifier (min 1 round), at the start of its next turn it drops to 0 HP and is dying. It can't regain hit points or be stabilized until it can breathe again.
If your concentration is interrupted, the target coughs up the water and begins breathing again.
1/3 cup of water
Inmergo Pulmonis Aqua