Hello!<br/><br/>Would you please help me about a conjunction 'for'?<br/><br/>Is 'for' different from 'because' or 'since'?<br/><br/>I can't distinguish. For example, <br/><br/><font color="#ff1493">It must be very cold outside, </font><font color="#0000ff">for </font><font color="#ff1493">the lake is frozen over.</font><br/><br/>In the above example, can I use 'since' or 'because' instead of 'for'?<br/><br/>If not, would you explain the reason with some examples?<br/><br/>Thank you!