Dear teachers, <br/><br/>Can you tell me the differences bewteen <b>1800s</b> and <b>1800's </b>and <b>until </b>and<b> till?</b><br/><br/>Just I have encountered with 1800s and 1800's but I do think they are the same. Am I right?<br/><br/>Thanks beforehand<br/><br/>Regards<br/><br/>Nata...