The phrase "primary constituents" is correct and usable in written English.
It is commonly used in linguistics and grammar to refer to the essential or main elements of a sentence. Example: The primary constituents of a simple sentence are subject, verb, and object.
"If you look at what a quark is, or an electron, the primary constituents of matter, they're pointlike particles.
But it is crystal clear that this is what his primary constituents want and expect from him.
"It's time for this museum to renew and strengthen its relationship with its primary constituents, which are the Indian tribes in this country," he said.
This surprising wave-particle duality is shared by all of the primary constituents of nature (e.g., electrons have both particle-like and wavelike aspects).
The primary constituents of the nucleus are the proton and the neutron, which have approximately equal mass and are much more massive than the electron.
The seven primary constituents of the body blood, flesh, fat, bone, marrow, chyle, and semen are produced by the action of the elementary substances.
Either way, the real pity for A.I.G.'s primary constituents — American taxpayers — is that as a foreign company, A.I.G. can't list A.I.A. in Shanghai — where the business was originally founded 90 years ago.
"I want a Europe, but I remain attached to my nation," he said, outlining a plan for a union whose primary constituents remain national governments, instead of the European people at large.
If students are not their primary "constituents," who are? How could they possibly be so obtuse (a good SAT vocabulary word) as to require high school students to sit for 3 hours 45 minutes?
Primary constituents are aluminum, nickel, and cobalt in various proportions, with small amounts of one or more of the elements copper, iron, and titanium added; the titanium-containing material is sometimes referred to by the trade name Ticonal.
The primary constituents of granite were quartz and feldspars.
