I have lived here for more than twenty years.我住在这儿二十多年了。
I have lived here since I was born. 我从出生起就住在这儿了。
I worked here for more than twenty years. (我现在已不在这里工作。)
I have worked here for many years.(现在我仍在这里工作。)
1)(对) Tom has studied Russian for three years. = Tom began to study Russian three years ago， and is still studying it now.
2)(错) Harry has got married for six years. = Harry began to get married six years ago， and is still getting married now.
显然，第二句不对，它应改为 Harry got married six years ago. 或 Harry has been married for six years.