The Monk’s Tongue of the Sun and Moon feature states:
Starting at 13th level, you learn to [touch the ki of other minds] so that you understand all spoken languages. Moreover, any creature that can understand a language can understand what you say.
“Touching the ki” clearly does not require the Monk to physically touch a target. But it does appear to be an active noun. Is “touching the ki” an active, conscious action, or a passive effect that happens all the time?
The new Bilgewater content contains 2 examples of this language, one for a passive effect, and one for an active:
Starting at 7th level, you learn to [exploit a foe’s weak spots], even if they appear to have none. The damage dealt by your firearm, including damage dealt via Firearm Upgrades, ignores resistances and immunities.
At 18th level, you learn to [channel the volatile force of your firearm’s black powder] into a single concussive blast. As a bonus action, you can either throw or set down a small explosive.
Tongue of the Sun and Moon doesn’t list an action, but that’s not to say that it is something that doesn’t require one.