 Tense Some theorists hold that sentences containing verbs in the present tense vary not only in truth-value from time to time, but also in content, from context to context. For example, some hold that the content of ‘Fred is hungry’ at a context whose associated time is \(t\) is (roughly) that Fred be hungry at \(t\). The variation in content is said to be due to the occurrence of ‘is’, which is context-sensitive. More generally, tense markers and tense morphology are claimed to be context-sensitive expressions. See Reichenbach 1947, Partee 1973, Enç 1987, Salmon 1989, Ogihara 1996, and King 2003.