BE VERY APPRECIATED ??

All four sentences contain one or more grammatical mistakes.
The general comments are:the "verb" following a modal verb (such as would, could) must be in its base form (i.e. like simple present tense)."very" cannot be used befoe a verb.It is better to use "very much" than just "very" in front of a past participle (acting as an adjective).."would" is based on an intention or willingness, whereas "could" is based on a condition or ability.Specifically:
I would be very appreciated if you could sent us a copy. ( 錯在那, 點解 )
Error (1) [could send] NOT [could sent]; (2) meaning is wrong. I am the one who appreciates, but not the one being appreciated, so " I would be appreciated" is wrong. (3) grammatically, very appreciated is not good; it should be "very much appreciated"

I could very appreciate it if you would send us a copy. ( 錯 or 對, 點解 )
Error (1) The meaning of "I could" is wrong. "Could" refers to the ability, so "the ability to appreciate" is obviously out of context. It should be "I would ...". (2) "very" cannot be put in front of a verb (appreciate).

I would very appreciated it if you could sent us a copy. ( 錯 or 對, 點解 )
Error (1) would appreciate NOT would appreciated (2) very cannot be put in front of the verb (3) could send NOT could sent.

I would very appreciate it if you could send us a copy. ( 錯 or 對, 點解 )
Error (1) "very" cannot be put in front of the verb.


Therefore, the correct sentence should be:
(1) I would appreciate it very much if you could send us a copy.
(2) It would be very much appreciated if you could send us a copy.
Also, for both sentences, it is okay to use "would send" as well.

只有第一句文法和用意上都對。

第四句文法上沒錯，但用意上不太formal，跟句子的用詞不配合。

其實只用寫：I appreciate it if you could send us a copy便可以了。太多修飾和客套語反而令全句「錯」寫的。

I would be very appreciated if you could sent us a copy. ( 錯在那, 點解 )
Tense 錯了, 應該是現在式 send﹐ 不是過去式 sent
I would be very appreciated if you could send us a copy of XXX
另一個寫法可以是 - I would appreciate it if you could send us a copy of XXX

點解用 would/could﹐ 晤係 will/can﹐ 因為這是假設 (你會寄一份XXX給我)﹐所有假設, 都要用過去式, i.e. could, would, might....If I were you, I would...
如果我係你﹐ 我會...
I could very appreciate it if you would send us a copy. ( 錯 or 對, 點解 )
錯, 情參考以上
I would very appreciated it if you could sent us a copy. ( 錯 or 對, 點解 )
錯, 情參考以上
I would very appreciate it if you could send us a copy. ( 錯 or 對, 點解 )
錯, 情參考以上