French phrase
Je maîtrise ~.
Meaning
I have a strong command of ___.
When to use it
Shows thorough knowledge of a field. It has a composed, professional tone and suits formal introductions or meetings.
Example dialogue
Avez-vous de l'expérience en négociation internationale ?
Do you have experience in international negotiations?
Je maîtrise la négociation internationale.
I have a strong command of international negotiations.