<p>The exchange between the teacher and the student promotes learning far different from that which results as the student listens but does not participate. </p>
<p>I know that "as" is wrong since it doesn't sound right. Could it be replaced with "if"?</p>
<p>Yes, ‘if’ could be replaced there since what follows is just an example of some other type of learning. That’s why ‘as’ doesn’t work because it indicates different degrees of an adjective, like ‘not as good as’. Where this sentence is just stating the learning is different, there’s no judgment made as to which is better or worse.</p>