string check - in a list

How can i check if one element in a list is a string?

The basic answer is to check the TYPE function:

(equal (type "abc") 'STR)

But may be useful to give more details of your issue; you want to validate the element from a certain position, or if the list contains (at least) one string, or other scenario?

Using vl-some:

(vl-some '(lambda ( x ) (= 'str (type x))) <your list>)

Another, recursive:

(defun _stringinlist ( l )
   (and l (or (= 'str (type (car l))) (_stringinlist (cdr l))))
)

I just wanted to eliminate strings from a list...thanks!

Then:

(vl-remove-if '(lambda(x) (equal (type x) 'STR)) listToProcess)