Hello!<br/><br/>Can you please tell me if the meaning of the phrase in the title is ''I couldn't tell the difference'' or ''I couldn't be sure''?<br/><br/>A:<i>'Did you see his face?'</i><br/><br/><i>B: 'I<font color="#0000ff"> couldn't tell</font>. It was so dark.</i>'<br/><br/>B was also drugged and also unable to see probably because of the drugs too.<br/><br/>Thanks