Use Localize when you teach the same words through a different language — the same English words explained through Russian instead of Spanish, for example.

Open the set’s menu and choose Localize, then pick the language.

What you get. A new, separate set. The original stays exactly as it was.

The new set:

• keeps every word and every example sentence;
• has empty translations — the old ones belonged to the old source language, so they are not carried over;
• is private, whoever could see the original.

What you pick is the source language only. The language you teach is the language of the words, and it does not change. A set that teaches English through Russian can become English through German; it cannot become German through Russian.

One localization per language. If the set already has a version in that language, the dialog offers to open it instead of creating a second one.