I remember reading somewhere that songs sung in English tend to have one note per syllable, and one syllable per word, and that that's how you tell when a song was composed in English.

Alas_(1w,2s) my love_(1s,2n) you do me wrong_(1s,2n)
To cast me off_(1s,2n) discourteously_(1w,5s,4n)

So what language was Greensleeves composed in?

The way I sing it, the two syllable 'Greensleeves' has, at different points, 2, 3 and 4 notes.

There are many, many more English songs that don't conform to the 'one note per syllable, and one syllable per word' tendancy.

DC