That doesn't really matter though. Maaya Sakamoto sings in English perfectly, but she revealed that she doesn't speak much English at all.
That explains why her first album for Macross Frontier is named Triangler. Some of us English speaking fans commented that it sounds quite senseless as a title itself, although it probably referred to the love triangle between Sheryl, Ranka and Alto.
LOL! That one was actually Yoko Kanno's fault! I've seen it written at "Triangler" and "Triangular", but either way it refers to love triangles from Frontier and the original Macross.
As for whether the girls speak English or not, maybe Sakyura could ask Riyu for us.