Present perfect
Video explanation
Examples
| Sentence | Source |
|---|---|
| We've developed this ability because it makes evolutionary sense. | The security mirage |
| It hasn't changed as we were growing up. | The security mirage |
| But for other tumors and cancer types, the improvements have only been modest. | Can we eat to starve cancer? |
| OK, who hasn't voted yet? | How stats fool juries |
| Apparently, only three people have viewed episode one. | Scrubs: Interns, s01e02 - Our Meeting With JD |