"no copula" . "dropped" . "invisible copula" . . "omits the copula" . "do not have a verb" . . "Zero copula" . "zero-copula" . "absence of copula" . . "zero-copula language" . "\\\"zero\\\" copula" . . "zero copula" . "frequently deleted" . "Zero copula" . . . "left out" . "null copula" . "Forms of the verb \\\"to be\\\"" .