Here's how Caterpillar works

Caterpillar converts any movie and subtitle file into a full language learning course using spaced repetition and targeted exercises to keep you focused on every word.



Inline content

Three core exercises designed to improve the essential language learning skills. Listening, writing, and speaking.

listen card

Replay as many times as you need

Easily replay segments of a film as many times as you want. You also have the option to listen to the audio at half-speed!

Record and listen to yourself

If you want to sound like a native, you need a way to hear your accent. Record yourself and listen back. Practice your accent until it sounds right to you.

repeat card
write card

Write what you hear

Watching movies is inherently passive. Not anymore. Listen carefully and write down exactly what you hear.

Have a look inside



Why should you use Caterpillar?

Watching is not enough

Different activities cause the brain to operate in completely different ways. Watching TV and movies pushes the brain into alpha mode (passive intake of information).

Beta waves are present when the mind is alert and focused on a task and alpha waves when the mind is relaxed, free to wander or daydream.
-Meghan Neal

Watching causes our minds to quickly enter alpha mode. We still process information as it comes in but are not actively concentrated or alert. This is why we say watching movies is inherently passive.

Caterpillar solves this problem by separating a movie line by line and creating exercises based on each short clip. Each bit of dialogue becomes its own unique exercise as you listen closely, transcribe word-for-word, and tune your accent with speaking exercises.

Focus on every word to master every word

Once we get past a certain level in a language, we focus less on the details and more on the general idea of each phrase. Not understanding 20% of the words in a film probably won’t keep you from generally understanding the plot especially when there are other visual cues (facial expressions, actions, etc…) to help you. Let’s say it’s only 20%. That 20% is made up of new words and culturally specific expressions. That 20% is the difference between actually learning something and maintaining your current level.

If you are watching movies to maintain your current level in a language, go for it. However, if you’re watching with the hope of improving, we think there’s a better way. That’s why we created Caterpillar.

The power of audio-visual learning

It’s amazing how much information gets lost if you’re not paying attention. Here at Caterpillar, we are native English speakers and there are few movies we can directly quote. French, however, is not our native language but we can quote specific phrases from movies we've used in Caterpillar along with the exact scenes in which they occur.

Just like you probably remember the exact context where you first heard certain songs, learning with Caterpillar gives you a complete movie worth of specific, contextual references to associate with new words and phrases. These visual aids are burned into the mind for later recall. Caterpillar even lets you replay clips at slower speeds to make sure you capture every word.

Imagining what you sound like isn’t the same as actually hearing yourself

Caterpillar includes a speaking exercise for each subtitle to help you sound as much like the actor as possible. That’s how you get a native level accent: speaking and critiquing yourself.

Of course, you could always ask a native speaker who also happens to be your best friend and is willing to spend hours correcting your accent. Most of us don’t have one of those so let Caterpillar be your best friend. If you want fast and efficient feedback on your accent and rhythm, you’ll need to listen to the actor, record yourself, listen to yourself, compare your voice to the actor, and repeat this process until you’re happy with the way you sound.


Your learning should be relevant to you. You choose what you want to watch

The great thing about Caterpillar is that it works for any language and any video as long as the video has a corresponding subtitle file. You can find subtitle files for most films and series using resources like Caption App and OpenSubtitles.org. If you want to use a DVD, subtitles can also be accessed from DVDs.

Constant translation doesn’t work

Translating word for word doesn’t really help you immerse yourself in your target language. As much as possible, you want to keep the mind from referring back to your native language for reference. However, when learning new vocabulary, sometimes translation is unavoidable. Caterpillar has a built in translator for all languages so you don’t need to interrupt your flow.


The best parts of language learning in one place.

Want updates and free language learning hacks?