The first key, learn pronunciation first, came out of my music conservatory training (and is widely used by the military and the missionaries of the Mormon church). Singers learn the pronunciation of languages first because we need to sing in these languages long before we have the time to learn them. In the course of mastering the sounds of a language, our ears become attuned to those sounds, making vocabulary acquisition, listening comprehension, and speaking come much more quickly. While we’re at it, we pick up a snazzy, accurate accent.
