I've taken a list of English words, and examined each of them to see what they sound like (using the PHP metaphone function). This page lists the most common metaphone codes, along with their words. You can also search for a word of your own, and see which words sound similar - and which ones rhyme, and which ones alliterate.
retain reattain retine retina retinue retinae rutin redan ratan radian retune rattan ratine retene ratany routine radon redon redeny ratoon ratten ratton redden rhyton ridden rotten redone ratteen rattoon written
attain tain reattain retain stain detain tan tin satin titan rattan retina phytane botany gittin betaine ratine dittany tine mattin patine biotin butane latina tiny stein tetany witan poutine shaitan ratany chitin mutine litany rutin phytin retine lattin patina cutin ratan seitan stane cetane mutiny latino satiny lutein matin patin routine cotan zeatin soutane gitano sheitan
ret arete treaty tread reared oread great create fretty fret bready bread rota read retie rete reata ready readd pretty dread treat tret