denounce -- den(o)unciation<br/>abound -- ab(o)undant<br/><br/>question: where is the 'o' vowel?<br/>Is there a rule that governs it or is it just a coincidence?<br/><br/>Which branch of linguistics deals with this problem. phonology? no?<br/>Do you know any good literature touching up on this problem?<br/><br/>Cheers