Tenses – Present perfect (past participle + ‘-ing’)

Tenses – Present perfect (past participle + ‘-ing’)

Example (1): The wind farm has been running for two years.
‘… has been running …‘
Example (2): They have been testing machines since last week.
‘… have been testing …’

Notes

Use this tense (sometimes without an ‘-ing’ form) whenever an event
starts in the past and continues into the present, i.e. something is
still happening, or somebody is still doing something, as in Examples
(1) and (2).

The preposition ‘for’ is used when referring to a period of time (‘for two years’), whereas the preposition ‘since’ is used when referring to a point in time (‘since last week’).