One common way to improve foreign-language skills is to watch videos in the foreign language. But if you’ve ever tried watching a foreign film, you know it can be quite difficult to follow along. Characters in movies talk in idioms, and faster than your high school French or German teacher might have done.

Even if you are fluent in a language, you might find it difficult to understand regional accents. A native English speaker from Texas who learned French in school could actually struggle more to understand Scottish English accents than textbook Parisian French.

Holger Mitterer and James McQueen wondered if video subtitles might help non-native speakers understand difficult accents. But what subtitles would work best? Mitterer and McQueen work in the Netherlands; would Dutch speakers learn to understand an accent better by watching an English-language movie with Dutch subtitles or English subtitles? Or would the subtitles hinder learning?