word usage - Are "right now" and "currently" exchangeably here?

Chapter 2 of the book "C++ Primer Plus, 6th Edition by Stephen Prata (2012)" says

Right now the main point to remember is that C++ syntax requires you to begin the definition of the main() function with this header:int main().This chapter discusses the function header syntax in more detail later, in the section “Functions,” but for those who can’t put their curiosity on hold, here’s a preview.

In Oxford dict "right now" and "currently" are synonyms.

Are "right now" and "currently" exchangeably here?

Answer

They are synonymous, but they have slightly different idiomatic usage.

"Right now" very specifically refers to this moment in time.

"Currently" is used in a broader sense, for ongoing matters that have already begun in the past - for example, the term "current affairs" refers to news bulletins that cover what has happened in a day or even a longer period such as a week. The latest edition of a monthly magazine may be termed "the current edition", even though it could be 29 days old.

In your text, I feel that "right now" is not interchangeable with "currently". It is telling you that, at the precise moment you are reading it, you should remember this main point.

Right now the main point to remember is that...

It reads as an instruction, advising you to remember a particular point now. Your quote even says that other matters will be discussed later in the chapter, which is why I am certain that "right now" refers to your present position in the book and not some real-world climate. As a learning manual, it is speaking to you very directly and meant to be read in order so that you learn the subject in a linear fashion.

Consider this order:

Turn around right now.

You can't say "turn around currently" - that doesn't make any sense.

An example where they are interchangeable:

• Currently, there are 4 major armed conflicts happening in the world.


• Right now, there are 4 major armed conflicts happening in the world.

They are interchangeable in this context because the events they refer to are both ongoing (and so "current") and occurring "right now", at this moment in time.