有關英文既問題想問下

Mary donates $100 to the poor.
Mary makes a (generous) donation of $100 to the poor.

上述沒有 adverbial phrase of time (last week, yesterday, today, tomorrow, ...)
Mary donates $100 to the poor today.
Mary donated $100 to the poor yesterday.
Mary will donate $100 to the poor tomorrow.

一分鐘前和一分鐘後放置在捐款箱不重要, 無需那麼執著 time frame
“Mary has (just, already) donated $100 to the poor’
意思Mary 剛剛(或已經) 捐了 $100 (暗示無需再叫她捐或 Mary不是經常捐錢)
Present perfect 有 perfect aspect (denotes “completed” 含意)

Present perfect 使用在"捐錢" 這樣用比較好 (個人意見)
Mary has donated considerable sums of money to the poor since she left school.

Note:
donate (verb) = 捐贈
donation (noun) =捐贈
the poor (plural) = people who are poor (窮人)



2014-08-02 08:07:11 補充：
donate (捐贈) 是 verb, 是有時態
Mary donates $100 to the poor. (Present)
Present simple tense 當然是講現在
重點不是講事實.
否則不用分 present, past, future
Mary donated $100 to the poor. (Past)
Mary will donate $100 to the poor. (Future)

在英語文法, 將私人做過或者發生事件當事實
You are inviting trouble!

2014-08-02 08:22:27 補充：
We often use Present Simple to state general truths and facts and to describe things which we feel are permenent situations.
不是私人做過或者發生的事件

Water boils at 100°C.
Broken bones in adults don't heal as fast as they do in children.

當mary所捐的錢到達箱裏時

Mary has donated $100.
這是現在完成時態動詞的精妙表達剛才發生了的情況

一般你就就算在同一天講mary剛才(可能是幾個小時前作出捐款)也可以這講/寫法。

但是假如她是昨天捐款而你在今天才跟朋友講述的話
則要用simple past tense過去時態的動詞了：
Mary donated $100 yesterday.

基本在描述donate這類自己/他人的行動時，很少機會會用donates(現在時態)的動詞的，因為英文時空邏輯上你損之前一刻是「未捐」，捐了的一刻是「已捐」，所以現在時態的動詞是不會用的，除非你表達mary那捐款的事實而不是描述情境，Mary donates $100 to XXX.並不是講她何時(現在)捐款，而是指出她這個叫mary 的人有捐款給這XXX機構的事實。