Polyglot
From Teflpedia
A polyglot (sometimes a linguist - though linguist has another meaning of one who studies linguistics) is a person who is multilingual, i.e. they have command of many languages.
Given English's status as the primary second language worldwide, it's likely that nearly all modern-day polyglots will speak English.
Polyglots can bring reflections of their previous language learning experiences to bear upon language learning.