 Propositions are thought to perform a number of other functions in addition to being the bearers of truth and falsity and the things expressed by declarative sentences. When a German and English speaker believe the same thing, say that the earth is round, the thing they both believe is not a sentence but a proposition. For the English speaker would express her belief by means of the sentence ‘The earth is round’ and the German speaker would express her belief by means of the different sentence ‘Die Erde ist rund’. Thus when people believe, doubt and know things, it is propositions that they bear these cognitive relations to. Finally, it is the proposition a sentence expresses, and not the sentence itself, that possesses modal properties such as being necessary, possible or contingent.