If you cast Polymorph on a non beast creature then cast Awaken on their beast form how much carries over after polymorph ends?
Polymorph does not give any explicit information on what happens to your statistics when the polymorph ends:
The transformation lasts for the duration, or [drops to 0 hp]. [...] The target's game statistics, including mental ability scores, are replaced by the statistics of the chosen beast. (Basic Rules, pg. 266)
So this leaves ambiguity when game statistics are altered during polymorph,
The charm effect of Awaken seems pretty clear from the logic shown here and reinforced by the specific wording referring to the target as a beast or plant during effects and a creature afterwards:
The awakened beast or plant is charmed by you [longer than polymorph.] When the charmed condition ends, the awakened creature chooses [...] (Basic Rules, pg. 216)
The other two effects of awakening (other than making a plant mobile) are less clear-cut:
The target gains an Intelligence of 10. The target also gains the ability to speak one language you know. (Basic Rules, pg. 216)
I would guess the modification to intelligence would apply to the beast's stats and therefore end with polymorph.
Language has been classified as being independent of creature statistics and act more as the character's experience. I'd argue the experience of a stranger turning you into a mouse, then gifting you the ability - as a mouse - to speak a language you have never used before would be an experience you couldn't lose I'm not sure if the language and intelligence granted from awakening should remain linked.
These are two examples I can see this having significant impact on my campaign:
- Meet an NPC I don't share a language with, Polymorph them then Awaken their beast form so they can speak my language. Can I now communicate with them when they turn back? If their original intelligence was higher then 10 is it reduced to 10?
- Say I use find familiar to get an owl (classified as a fey) familiar, then polymorph it to an owl (classified as a beast) so my druid friend can cast Awaken on it, does my familiar keep an intelligence of 10 and/or the ability to speak?
So after reverting from an awoken polymorphed state would you keep the 10 intelligence and a new language, only the new language, or not keep either?