Sometimes it has an extra refrain, example:

In Amsterdam there lived a maid
Chorus: Bless you young woman
In Amsterdam there live a maid
Chorus: Mark well what I do say
In Amsterdam there lived a maid & she was mistress of her trade

Chorus:I'll(we'll)go no more a-rovin with you fair(false) maid
Grand Chorus: A-rovin, a-rovin,a-rovin's been my ruin
I'll (we'll) go no more a-rovin with you fair maid.

Shay say it may have started off it's life back in 1640, in "The Rape Of Lucrece", Hugill doesn't believe this & Doerflinger does't say, but they all agree that's it very old. Most of the song has been prettied up of it's fowl language,to make it printable, so what you see now is probly not what it once was. Barry