I haven't seen my parents ... a long time.
I haven't seen my parents for a long time.
Il existe un lien avec le présent.
We have been walking ... 10 o'clock in this morning.
We have been walking since 10 o'clock in this morning.
L'heure indique le point de départ de l'action.
Ever ... I've moved to France, I can no longer speak English.
Ever since I've moved to France, I can no longer speak English.
S'utilise avec le present perfect.
I have lived here ... I was 10 years old and I still get lost.
I have lived here since I was 10 years old and I still get lost.
Marque le point de départ.
How long is it ... you last went to the cinema?
How long is it since you last went to the cinema?
Se traduit par "depuis".
She has been studying ... this morning.
She has been studying since this morning.
"this morning" fait référence à un temps précis.