Because 引导句子放前面，后面要加 逗号？

Question

Because he was ill , he didn't come here.

是吧？

2.能用he is ill. 不？

Answer 1

@@@1，要加，
2，不能，因为已经生过病了，是过去式。

参考：
because
conj.
因为
John didn't attend the meeting because he was ill.
约翰没有出席会议, 因为他病了。
B-he is tired, he does not want to go with us.
因为他太疲劳所以他不想和我们一起去。
I criticized him, not because I hate him but because I love him.
我批评他不是因为我恨他而是因为我爱他。

Answer 2

没错`
2.不能,因为从句和主句要时态一致

Answer 3

如果单单只有 He was ill. He didn't come here.
只能写成两句。

He didn't come here because he was ill.

Answer 4

Because引导的句子不能放句首。放后面，前面用逗号。不能用is ill .