Pertain rhymes with:
ascertain, entertain, abstain, aquitaine, ascertain, attain, brattain, buntain, butane, chastain, contain, costain, detain, entertain, fontaine, fountaine, lafountain, lafountaine, lamontagne, maintain, mustain, obtain, partain, petain, retain, sartain, stain, sustain, uptain
Pertain sounds like:
paradyne, parden, pardini, pardon, part-time, partain, parten, parthenia, parthenon, parthian, partin, partition, partney, parton, parttime, partum, pepperdine, perdomo, perrodin, pertamina, portadown, portion, portman, portney, portnoy, predation, predawn, preordain, preteen, prettyman, proration, protean, protein, protium, proton, pruden, prudhomme, purdham, purdin, purdom, purdon, purdum, puritan