It's kind of reassuring - and at the same time, concerning - that even a game with production value as high as Baldur's Gate III frequently falls into the trap of voice actors (VAs) emphasising certain lines on the wrong word for the context at hand.
To explain what I mean in general, consider that even a simple sentence like "Why did you buy this book?" changes in meaning drastically, depending on the emphasis:- WHY did you buy this book? (what's the motivation)
- Why DID you buy this book? (as opposed to not doing it)
- Why did YOU buy this book? (as opposed to anyone else buying it)
- Why did you BUY this book? (instead of stealing it
)
- Why did you buy THIS book? (instead of any other book)
- Why did you buy this BOOK? (instead of anything else)
Maybe it's just me, but it really detracts from my immersion when I can clearly tell from the subtitles the sentence I'm hearing was supposed to be emphasised differently than the way the VA did. This is even more apparent when the subtitles feature the to-be-emphasised word in italics, but the VAs emphasis is elsewhere.
And in a game as long as BG3, this occurs more often than I would have expected - too often to remember all instances.
Here are just two examples off the top of my head - there are many more, would be interesting to compile them all here. 
1) Between Shadowheart and Dame Aylin after Shadowheart has saved her:
Shadowheart: "What will happen now?"
Aylin: "Not what will happen. What will you do?"
The VA emphasises this line as "not what WILL happen - what will you DO?"
When the juxtaposition is clearly supposed to highlight Shadowheart's agency, i.e., "not what will HAPPEN - what will you DO?"
2) Dammon at the end, before the final battle, if he is one of your allies:
Dammon: "I'm better at crafting steel than wielding it."
The VA emphasises this line as "I'm better at crafting STEEL than wielding it"; the context would make you expect him to say, "I'm better at CRAFTING steel than wielding it".
In other games, this is even more prevalent: I've heard VAs mispronounce important terms from the setting, and yet, the falsely-pronounced take gets used in the final version of the game. (In the German version of the first Lego Bionicle game, for example, Toa Pohatu at one point pronounces "Turaga", the priests of the setting, as "Taruga" instead.)
In BG3, I've only noticed this problem to a lesser extent when it comes to the fictional languages in the setting - most notably, the gith language, but also some drow terms - as the different VAs couldn't quite seem to agree on how they should be pronounced =D :
Some gith will pronounce "ghaik" as written, whereas Lae'zel pronounces it "gaikh". Another notable example is the sentence "Gith'ka tav'kim krash'ht", said by multiple gith characters, but some pronounce the last word like "crush it", with two syllables, whereas Orpheus will only say "krasht", as one syllable.
For drow, it's the word "straj" that features different pronunciations between different characters.
Another pet peeve is characters ignoring even the most apparent grammar of their own language. I doubt the gith language has been developed as far as the Tolkien or Star Trek languages, meaning that you could actually speak it. However, what little grammar has been defined for it is so obvious, even to a new player, that it's really irritating whenever even that simple grammar is being ignored.
Gale when you first talk to him after recruiting Lae'zel:
"A githyanki joining our group."A singular member of the githyanki people would logically have to be a githyank. As the word "githyanki" means "children of gith", githyanki children would consequently be "githyanki yanki" =D.
We even hear the same word stem before, when Lae'zel calls Shadowheart "kainyank". I'd expect an educated man like Gale to know this. :P
Then again, Gale also tells the Dark Urge that memory loss were no symptom of ceremorphosis, at least not according to any book he read on the subject - whereas Lae'zel will say it is, since the parasite takes all of you, "body, mind, and soul".
Perhaps Gale simply isn't as well-read as we're commonly led to believe?
More likely, it's a writing inconsistency similar to Minthara's different recounts on how she got tadpoled: At one time, Minthara claims Orin forced the tadpole into her eye herself; another time, she says Orin merely held her head in place while a mind flayer inserted the tadpole. Of course, you could still count the latter as "Orin implanting the tadpole herself", but it's a very different image than what I for one had in mind when hearing the first version of that story. Thus, it sounds like Minthara outright contradicting her own words.
As far as grammar mistakes are concerned, it's far more immersion-breaking, of course, when githyanki characters themselves forget the grammar of their own language:
Lae'zel at points refers to "the kith'rak" when talking about multiple of them, so it should be "the kith'raki".I'd expect the same for other gith words ending with "-k", like "istik - istiki", though you will more frequently here "istiks" for the plural. That however I can let slide, assuming the gith are just using common (English) grammar on their own gith loanwords when speaking in common.
Those examples however are of course much less obvious than the falsely placed emphasis in the regular English voice lines in the game.
Given that I'm observing this with some level of frequency even in a game that had as much effort put into it as BG3, I'm suspecting a systematic cause behind it - and I wonder what that might be?Do the VAs receive the lines they are supposed to record without the context the sentence is said in? I could understand that if the VAs are recording their lines at home, in their own studio, and then just send them in. But with all of the MoCap in BG3, and a director present, shouldn't it be obvious to everyone when the emphasis is off for a given sentence?
