【问】 go的现在完成时是have gone因此，我认为He is gone.是错误的。

【答】 在He has gone to a party.中的has gone是现在完成时(gone为过去分词)，而在He isgone.中is为系词，gone为形容词，作表语(主语补足语)。后一结构着重强调的是状态。

1. “Father!” cried Fenella. But he was gone. (Mansfield)

“爸爸!”芬内拉喊道。但是，他已经走了。

2. How long do you think you'll be gone? (Dreiser)

你估计你要离开多久?

3. Their cousin was already gone out when they came down to breakfast. (Macaulay)

当他们下来吃早饭时，他们的堂兄弟已经离开了。

be gone的主语是“物”时，常常表示“消逝了”、“不见了”、“用完了”。

1. When I came back my car was gone. (PEU)

当我回来时，我的汽车就不见了。

2. Just a pain in my chest. It's gone now.

刚才我的胸疼。现在好了。

3. Is the butter all gone? (PEU)

黄油全吃光了吗?

4. “Well，one day Fred and I went down to the sheep pasture to salt the sheep，when Icalled them together，my great prize sheep was gone. ”

“是这样，一天我和弗雷德去牧羊场给羊喂盐。当我把羊圈起时，我发现我那最好的羊不见了。”

have come与be come的情形也是如此：

The summer was come now. (Maugham)

夏天到来了。

[参见come(he has come/he is come)]