Question

Ram was standing in the bus stop ____ morning.
(since/from)

Answer 1

Ram was standing in bus stop since morning

Answer 2

heya!!

Ram was standing in the bus stop ____ morning.

Ram was standing in the bus stop since morning.

Reason - from is used only for a particular time period like, " from 1970 to 1991".

While since is used only when there is only the starting period which will go long, like "since 2005" which hasnt end till now.

hope it helps!!