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.
chirper chirpier sharper
chirper raper chirpier warper dripper draper dorper puerpera proper larruper gripper riper gripier griper carper harper roper ripper tripper groper sharper
chirp chirpy charpai charpoy chirrup chirrupy