Macmillan Online Dictionary
Definition of the present perfect: in English, a verb tense that expresses an action <that was completed at some time in the past, or> wrong, that's what the past tense does that started in the past and continues into the present, i.e, it's on-going. Right.
The tense is formed by combining the present tense(s) of "have" and the past participle of a verb, right, as in the sentence "She has paid the bill". Wrong. She paid the bill. "Paid" has no capacity to continue into the present. It's past. It's over and done. If it's on-going, she is paying the bill.
She lived in Nashville for 10 years (but now lives in Amarillo).
She has lived in Nashville for 10 years (and still does).
This is Exhibit # 119 to my assertion that there is at least one perfect error on any grammar website or in any grammar text you can name. In this case, a grammar item in a dictionary is close enough, don't you think?
.brad.11octo10.
It continues to amaze me that grammar teachers allow such items to exist. Doesn't the teacher assume the student will look things up in the dictionary (even via Google, which is how I found it)?