An Emacs Lisp function for detecting etre-verbs:

(defun eprime-buffer (&optional eprime-buffer-nlines)
  (interactive "P")
  (occur eprime-regexp eprime-buffer-nlines))

(defcustom eprime-regexp
  "\\W\\(is\\|are\\|be\\|were\\|was\\)\\W"
  "The regular expression to use when E-prime editing a buffer.
Seeks out whole words in the state-of-being form."
  :group 'my-vars
  :type 'string)

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