Actions, etc. continuing into the present

9.25.1 The present perfect + adverbials that suggest 'up to the present'

We do not use the present perfect with adverbs relating to past time (ago, yesterday, etc.) [> 9 18, App 48]. Adverbial phrases like the following are used with the present perfect because they clearly connect the past with the present moment: before (now), It's the first time so far, so far this morning, up till now, up to the present Adverbs like ever (in questions), and not ever or never (in statements) are commonly (but not exclusively) used with the present perfect:

I've planted fourteen rose-bushes so far this morning

She's never eaten a mango before Have you ever eaten a mango?

It's the most interesting book I've ever read [compare > 6.28.1]

Olga hasn't appeared on TV before now

9.25.2 The present perfect with 'since' and 'for' [> 7.31-32, 10.13.5]
We often use since and for with the present perfect to refer to periods
of time up to the present. Since (+ point of time) can be:
- a conjunction: Tom hasn't been home since he was a boy

The simple present perfect tense

- an adverb: / saw Fiona in May and I haven't seen her since

- a preposition: I've lived here since 1980 Since, as a conjunction, can be followed by the simple past or present perfect:

/ retired in 1980 and came to live here I've lived here since I retired (i e. the point when I retired: 1980) / have lived here for several years now and I've made many new friends since I have lived here (i.e. up to now)

For + period of time often occurs with the present perfect but can be

used with any tense. Compare: I've lived here for five years (and I still live here) / lived here for five years (I don't live here now) / am here for six weeks (that's how long I'm going to stay)

Actions, etc. occurring at an unspecified time