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.
tearful tearfully dareful trayful deerfly direful trefoil trevally direfully travel travail trivial
earful fearful jarful carful tearful barfly farfal farfel ireful careful dareful direful trayful weariful cheerful