SpaceX becomes first private company to launch humans into orbit. Source
Is it correct to use "the first" or "a first" here?What's the difference among them if so?
SpaceX becomes first private company to launch humans into orbit. Source
Is it correct to use "the first" or "a first" here?What's the difference among them if so?
"SpaceX becomes first private company to launch humans into orbit"
Sounds like a media headline. And headlines often shorten language that way. The whole sentence sounds very unnatural in any other context.
"The first" because there is only one "first" being referred to.
You could write, "SpaceX launched humans into orbit, a first for the company," but that would be specifically limiting it to SpaceX -- it would still be true if a dozen private companies had launched humans into orbit already.