Is there any diference in the use of prepositions "on/at" with the noun "stage", in the following example:
"On/at the technology demonstration stage..."
Could you please help me with it?
I found another preposition and it's "in" in the Longman Dictionary:
"Sometimes there are problems in the early stages of a project."
"This plan is still in its formative stages."
"We have several ideas in various stages of development."
However other examples use "at":
"At one stage I had to tell him to calm down."
"Four out of ten people are likely to contract cancer at some stage in their lives."
"At this stage his wife did not realise he was missing."
"I can’t change my plans at this late stage."
Is it similar to the the case with "in the end/at the end of smth", only with the reverse usage?
Could you explain it to me, please? Why use "in" rather than "at"?
But you could say "In the early stage ..."
You could also say "During the early stage/s ... " and most likely a few other prepositions as well, depending on the context.
But you can't use "on" for/with this meaning.