YOU SAID:

Yes I know he but he left yesterday so I can't tell him.

INTO JAPANESE

はい、私は彼を知っていますが、彼は去ったので私は彼に話すことができません。

BACK INTO ENGLISH

Yes, I know him but I can not speak to him as he left.

INTO JAPANESE

はい、私は彼を知っていますが、彼が出て行ったときに私は彼に話すことができません。

BACK INTO ENGLISH

Yes, I know him, but when he leaves I can not tell him.

INTO JAPANESE

はい、私は彼を知っていますが、彼が去ると私は彼に話すことができません。

BACK INTO ENGLISH

Yes, I know him, but as he leaves I can not speak to him.

INTO JAPANESE

はい、私は彼を知っていますが、彼が去るにつれて私は彼に話すことができません。

BACK INTO ENGLISH

Yes, I know him but I can not speak to him as he leaves.

INTO JAPANESE

はい、私は彼を知っていますが、彼が離れるにつれて私は彼に話すことができません。

BACK INTO ENGLISH

Yes, I know him but I can not speak to him as he leaves.