Question

18. The little girls have been dancing
8am.
i since
ii for
iii till
iv by​

Answer 1

The little girl have been dancing since 8 am.

Answer 2

Answer:

The preposition fitting your sentence is for.

Here’s a sweet tip : when thinking of time, whatever you can’t see on the clock uses for.

Four hours. Can you find it written on a clock or a watch? Nope ! Hence, for.

Conversely, exact time frame references such as 9:45, 4 o’clock, 2 p.m., 10:15, etc. ; do you see them on the clock/watch ? Yes, very much so. Ergo, you have since.

So to complete your sentence, you have - “She has been dancing for (the last) four hours”.

I insert brackets around ‘the last’ for the plain reason that the moment the preposition for is used, the two words become redundant. For in itself implies the last or previous ‘x’ hours. So the usage is entirely optional.

Had you, however, known the exact point in time (say three in the afternoon) when she took to dancing, your sentence would’ve looked something like as follows :

“She has been dancing since 3 p.m.”.