Bonjour,
ago = il y a
since = ( point de départ ) depuis
for = ( durée ) depuis
Réponse :
Grandma was in Paris two weeks ago.
He has been on the phone since two o’clock.
Attention : since two o'clock.
(=> depuis deux heures ( l'heure marquée sur l'horloge/point de départ ))
for two hours.
(=> depuis deux heures / durée )
He has flown this plane for ages.
They have been married for ten years.
He started delivering letters twenty years ago.
It has been raining since Monday.
He sold a new house two days ago.
He has been recycling since January.
They have been in love for three years.
;)
