Question

There's an apple on the table 怎么改为否定句，一般疑问句，还有肯定回答

There's an apple on the table 怎么改为否定句，一般疑问句，还有肯定回答和否定回答

Answer 1

否定句 there isnot apple on the table 因为桌上没有苹果 无需冠词
疑问 is there have apple on the table?

Answer 2

否定句：there is no apple on the table.
一般疑问句：is there any apple on the table？
yes，there is/are。
no，there isn't.