Fans were a tad frustrated and confused that after debuting in Avengers: Age of Ultron, Wanda Maximoff quickly lost her Sokovian accent. Years ago, speaking on Josh Horowitz's Happy Sad Confused podcast, Joe and Anthony Russo explained how and why Wanda no longer had her distinct accent:
“We have intentionally tried to strip that accent away for a couple of reasons. One is you’ll notice at the beginning of Civil War that Black Widow is training her to be a spy, and two is she’s been on the run, and one of the most distinguishing characteristics that she has is her accent.”
Despite this explanation, Wanda's accent still isn't present in WandaVision, while the Disney + show makes reference to the fact that she's European and Sokovian in the very first episode. Elizabeth Olsen was directly asked about Wanda's lost accent and rebukes that it is lost and that she still has it.
When the topic of Wanda's accent came up on a recent episode of Collider Ladies Night with Elizabeth Olsen, she decided to address the issue and state that Wanda's accent “hasn't gone anywhere” and further implies that Wanda simply hides it, especially in WandaVision when “she is playing the role of being in an American sitcom.”
Olsen explains that her accent was created alongside Aaron Taylor-Johnson's own accent, which compensated for his British accent:
“So, the Sokovia accent was created by me and Aaron and our dialect coach because it’s a fake country and we could find different sources of Slavic sounds. And we wanted to make sure it didn’t sound Russian because Black Widow speaks Russian, and so we just needed to sound more like Slovakian. So we created these sound changes that worked for Aaron’s British accent going to Slovakia basically and my American accent so that we sounded related."
It seems to be implied by Elizabeth Olsen that Wanda hasn't lost her Sokovian accent, but that she's merely hiding it well in Wandavision:
"And then all of a sudden, all these different characters had to speak it in different films. So the Sokovian accent took a lot of time. It hasn’t gone anywhere. There have been reasons for everything. It lightened up when she started living in the States, and in WandaVision she is playing the role of being in an American sitcom and so it’s not gone. It is absolutely still there.”
WHAT THIS MEANS
The fact that Elizabeth Olsen insists that Wanda hasn't lost her Sokovian accent might mean that fans will hear it again, perhaps later on in WandaVision's run. Maybe during a tense moment with Wanda in distress, her accent last heard in Avengers: Age of Ultron might slip through.
It is also possible that Olsen is saving face with certain fans disappointed that Wanda no longer has her accent. Most of her explanation is quite similar to the Russo's, who also said that Wanda has been hiding it, even when it was just between herself and Vision like in Avengers: Infinity War. It could be interesting if Wanda purposefully attempted to bury that part of herself. Wanda's accent slipping could further show the illusion she's built up for herself breaking.