"Terrans are not smart."
I'm pretty sure it isn't.
The verb is valbe' "are not smart".
The subject is tera'nganpu' "Terrans".
So "Terrans are not smart" is valbe' tera'nganpu'.
The chaH just sort of hangs there at the end, doing nothing.
A bit like "They Terrans are not smart".
"They Terrans" doesn't make sense; it's two noun phrases (a pronoun and a noun) next to each other in a position where only one noun phrase is expected (the subject).