opanowaniu 英語で:

He mastered English easily.

A foreign language cannot be mastered in a year or so.

English cannot be mastered overnight.

What he was taught he mastered.

With all of his tricks he has mastered, he will be able to deal with any formidable client.

Jim mastered French and German.

Have you mastered English, or is it English that has mastered you?

Esperanto, with its 130-year history and abundant literature, can be mastered in one tenth of the time required for learning one of the widespread national languages.

Uncontrolled, these forces may be dangerous and destructive, but once mastered they can be bent to man's will and desire.

You know you've really mastered a foreign language when you can write a decent poem in it.

I was pleased with the rapidity with which he mastered Japanese.