The following sentence is quoted from <b><i>The Practice of English language Teaching</i> (First published 1991, written by Jeremy Harmer)</b><br/><br/><u><i>We <font color="#ff0000">do </font>not only have to show students what language means, we also have to show them how it is used.</i></u><br/><br/>I think <font color="#ff0000">do</font> should be deleted from the above sentence. Am I right?