应该注意两点：

（1）appreciate 表示“感谢”的意思时，只能用表示事物的而不是表示人的词语作宾语。

（2）appreciate 表示“欣赏”、“感激”的意思时，是及物动词，可用名词或者动名词作宾语。与if 或者when 从句连用时，必须用 it 作形式宾语。

appreciate 后面接什么成分要取决于这个单词语义/意思【appreciate+名词(sth)/代词(sth)/动名词(doing)/that从句】

【1】appreciate  vt.欣赏；赏识；鉴赏,重视 【appreciate+名词/代词】

You can't really appreciate foreign literature in translation.

看翻译作品不能真正欣赏到外国文学原著的美妙之处。

His talents are not fully appreciated in that company.

他的才干在那家公司未受到充分赏识。

Her family doesn't appreciate her.她的家人不重视她。

Anyone can appreciate our music.任何人都能欣赏我们的音乐。

In time you'll appreciate the beauty and subtlety of this language.  

总有一天你会体会到这门语言的优美和微妙之处。

【2】appreciate  vt.感激；感谢；欢迎【appreciate+名词/代词/动名词/it +when/if从句】

We appreciate your helping us.谢谢你帮助我们。

He appreciates being advised.他得到忠告,十分高兴。

He appreciates being advised. 他很感激得到了建议。

I'd appreciate some help.如果有人帮忙我将非常感激。

Your support is greatly appreciated.十分感谢你的支持。

Thanks for coming. I appreciate it .谢谢光临。无任欢迎。

I would appreciate it if you paid in cash.假如你支付现金的话，我会不胜感激。

 Peter stood by me when I most needed it. I'll always appreciate that

当我最需要的时候，彼得在我身边支持我。我将永存感激。

Thanks, lads. I appreciate it.谢了，哥们儿。我很感激。

I would greatly appreciate it if you would send me the application forms as soon as possible.
若能尽快寄来申请表格,我将不胜感激。

【3】appreciate  vt.理解；意识到；领会，认识【appreciate+名词/代词/that从句】

She never really appreciated the depth and bitterness of the Irish conflict.

她从来没有真正认识到爱尔兰矛盾的深刻和激烈。

I appreciate the task will be long and difficult.我懂得这项任务是长期而艰巨的。

 He appreciates that co-operation with the media is part of his professional duties.  

他懂得与媒体合作是自己工作职责的一部分。

What I failed to appreciate was the distance between the two cities.

我没有意识到这两座城市间的距离。

I don't think you appreciate how expensive it will be.我想你不了解它会有多昂贵。

We didn't fully appreciate that he was seriously ill.我们没有充分认识到他的病情很严重。