<span style="color:#ff0000;">1-He must not have heard the phone ring.</span><br/><span style="color:#ff0000;">2-He must have not heard the phone ring.</span><br/><br/>Are both these sentences correct?<br/>Is there a difference in their meanings?<br/><br/>I find "2" a bit strange.<br/><br/>Gratefully,<br/>Navi.