Regarding my post, I want to [strike]give[/strike] get more clarity. I read on a website that “since" and "for” are used [strike]in[/strike] with the present perfect [strike]continues[/strike] continuous tense but the [strike]below[/strike] first sentence below is without it.
I have been waiting all day. (I am unable to understand this sentence.)
She has been [strike]studding[/strike] studying for two hours. (Present perfect continuous)
"Since" and "for"
can be used with the present perfect continuous but that doesn't mean that "since" or "for" will appear in all sentences written in the present perfect continuous which also contain a time statement. We don't use it before "all" when "all" means "the entire".
I have been waiting all day = I have been waiting for the whole day.
She has been studying all morning.
She has been studying all night.
She has been studying all day.
She has been studying for two hours.
She has been studying for eleven hours.
She has been studying for a month.
She has been studying for seventeen weeks.
She has been studying English for two years.
She has been studying since 12 o'clock.
She has been studying since 7am.
She has been studying since December.
She has been studying since the autumn.
She has been studying English since 2011.