For English songs written in stanzas there are "meters" that describe the number of syllables in the lines & how many lines. Since the commonest number of lines is 4 that is not always stated. You can see it used most often in hymn books & religious tune books. The poetry is marked with the meter & the tunes list their meter.

Hymnals frequently have meter indexes. Heres the one for the Sacred Harp. Here's the one for Cyberhymnal

The most frequently used meters are named:
CM (Common Meter 8,6,8,6) 4 lines of poetry numbers of syllables.
CMD (Common Meter doubled, ie 8 lines of alternating 8,6's)
LM (Long Meter 8,8,8,8)
SM (Short Meter 6,6,8,6)
HM (Hallelujah Meter, 6,6,6,6,8,8; sometimes Lenox meter

Less used are just listed by syllables.
8s,7s is short for 8,7,8,7
7s means four lines of 7

It can get more complicated when choruses are added. The chorus can be of a different meter from the basic text.

Amazing Grace, Gilligan's Island & loads of other English poetry are CM, that's why you can swap the tunes & why it's called Common meter.