You'll have to pay extra if you want The Lord of the Rings: Gollum in Elvish
UPDATE 18/4/22: Gollum game developer Daedalic has responded to news of the game’s DLC which adds Elvish spoken language to the game.
In a statement shared with Eurogamer, Daedalic says you will still hear some Elvish (Sindarin) language without the DLC “from time to time” – though this paid DLC does fills out the game’s world with more, recorded by “professional voice actors… trained in Sindarin by our lore experts”.
The full statement lies below:
“The Elves in the base game will speak in their tongue (Sindarin) from time to time,” Daedalic said. “On top of that the Sindarin VO expansion adds additional Sindarin lines to some of the characters in the background. While traversing through Mirkwood and other parts of middleearth Gollum will be able to listen to various dialogues between Elves. These dialogues add to the atmosphere and worldbuilding. With the Sindarin VO these dialogues will be held in Sindarin.