Hi, <br/><br/><b>Question:</b><br/>Someone told me my sentence has problem, but he did not tell me what the problem is.<br/>Could you please tell me any mistake on the sentence?<br/><br/><b>Note that:</b><br/>I will speak this sentence, not write.<br/><br/><b>Sentence:</b><br/>There are 2 students. One of them understands question 1, but the other doesn't.<br/><br/>Thanks