The paper discusses some issues that arise from research on sign languages in the area of formal semantics. Sign languages provide a unique standpoint to investigate semantic phenomena like donkey anaphora, indexical reference shift, and tense. Moreover, they pose a challenge for semantic theories, since movement verbs display gradient properties (semi-continuous variations with semantic import). The paper presents and discusses some accounts that have been proposed.(2) $ i man i broke the bank at Monte Carlo, and he i recently died a pauper.According to other theories, the pronouns in (1) are disguised definite descriptions: for example, (1c) is interpreted on a par with (3) below, where the description ''the man