The distinction between strong and weak adjective forms, already greatly simplified by the Middle English loss of the final n, completely disappeared with the further loss of [ǝ] from the end of words. The loss of final [ǝ] also eliminated the distinction between plural and singular adjectives. Although the letter e, which represented the schwa vowel in spelling, continued to be written in many words, often haphazardly, adjectives no longer had grammatical categories of number or definiteness. The Modern English adjective thus came to be invariable in form. The only words that still agree in number with the nouns they modify are the demonstratives this–these and that–those.