(define (checkType . x)
  (cond
    [(vector? x) (display "x is a vector")]
    [(list? x) (display "x is a list")]
    [#t (newline)]
  ))

> (checkType (make-vector 3 #(1 2 3)))
x is a list

> (checkType (make-vector 3 #(1 2 3)))
x is a list

> (vector? (make-vector 3 #(1 2 3)))
#t

> (list? (make-vector 3 #(1 2 3)))
#f