詢問一些有關現在完成式既野

yes you are right

mary has patd $50 for a toy car(present perfect tense)

因為現在唔系說她生前一共買左幾多部玩具車，俾幾多$，是說她在2010年俾左$50 買一部玩具車.

更多了解有關past同present perfect的分別：https://www.youtube.com/watch?v=Dkln8PfE1xE

全部都系自己每個字打出來

Hope i can help you ！：D

You have been born (aged35) for 35 unchanged general factual years
Mary has paid since she were alive as if it were also a general fact.
Error and Corrections:-2050=2015? is a general problem lee.
and Not an eternal truth (problem) lee.

To 發問者：Fu :

你怎樣預知 Mary 在 2050 年死? 距今 35 年
如果 take time into consideration, "Mary has paid $50 for a toy car." 是錯

You have been born 用現在完成式是否正確? 同樣亦都改變唔到既事實

2015-03-22 02:35:43 補充：
To TOMING88:

是不會講 "You have been born." ,
會講 "Were you born in Hong Kong?" ~ 用 Past simple tense
發問者或許誤解已經出生了, 可用現在完成式
或者出生這件事對現在有關連, 否則現在自己不存在
假定香港出生既事實, 亦不會用 Present perfect

原句 Mary 死不死是 irrelevant.
我們要小心回答, 否則發問者會更混亂

說話並唔係咁講！！！！

要視乎你指出該事實的情況！！！

可以是 past tense, 可以是 past perfect tense, 不一定是 present perfect tense。

再講，你係唔係當講的時候是 2015 年先？