题目内容：

if you know when he will ccome,please let me know .改为同义句
同上

优质解答

如果仅仅要求改变句型,用原句词汇可以是：
Please let me know if you know when he will come.
如果要求改用其他说法表达相同意思：
Please inform me if you are aware of the time he will come.