Do offline translation apps actually work?
Why offline is worth setting up before you travel
Precisely because the moments you need translation most are the moments you are least likely to have data: landing in a new country, on a train, underground, or with a SIM that has not activated yet. Downloading the language pack takes a minute at home and is useless to arrange once you need it.
How to phrase things so it translates well
Short sentences, one idea each. Avoid pronouns where the reference is ambiguous, and avoid negatives stacked together. "Where is the train station?" survives any translation system; "You wouldn't happen to know if the station's still open, would you?" does not.
Reading the translation back and checking it makes sense in reverse catches most serious errors before you show it to someone.
What not to rely on it for
Anything legal, medical, or contractual. Machine translation is confident even when wrong, and it does not signal uncertainty. For a pharmacy conversation about a medication or a document you are being asked to sign, get a person.
Names and places also translate badly. It is often faster to show the written original than to translate it.
Our iOS app for exactly this. Runs on your device — no account, no tracking.