a long time
fixed phr.. A1 Beginner Oxford
fixed phr.. A large amount of time, like many hours, days, or years.
fixed phr.. An extended duration or period, functioning as a noun phrase often used adverbially.
It takes a long time to learn a language.
We waited for the bus for a long time, but it never came.
She stared at the painting for a long time, contemplating the artist's intricate brushwork and hidden symbolism.
Usage
Often used with prepositions like 'for', 'in', or 'after' to specify a duration.
Teaching tip
Contrast 'a long time' (noun phrase) with 'long' as a standalone adverb (e.g., 'How long will it take?').
Pitfall
I didn't see him since a long time.I haven't seen him for a long time.Use 'for' or 'in' with the present perfect tense to talk about a duration, not 'since'.