Небольшой урок грамматики об использовании английских слов «for» и «since».
It is possible to leave out the word for.
«I’ve lived here for seven years» is the same as saying
«I’ve lived here seven years.»
Both are perfectly correct. But in negative sentences, we almost always use for:
«She hasn’t seen him six months» is wrong. Instead we’d say «She hasn’t seen him for six months.»
And with expressions like all morning, all my life or all day, we never use for:
«He’s lived there all his life» not «He’s lived there for all his life.»
We use since when we mention a point in time in the past, when something began.
since 2003; since last January; since 4 o’clock
since July; since breakfast time; since the war
So, to recap.
We use for and since to talk about how long something has been happening.
We use for with a period of time and we use since with a point in time.