In this article I defend the view that many central aspects of the semantics of tense are determined by independently-motivated principles of syntactic theory. I begin by decomposing tenses syntactically into a temporal ordering predicate (the true tense, on this approach) and two time-denoting arguments corresponding to covert a reference time (RT) argument and an eventuality time (ET) argument containing the verb phrase. Control theory accounts for the denotation of the RT argument, deriving the distinction between main clause and subordinate clause tenses. The theory of covert movement is used to account for the independent/indexical interpretation of relative clause tenses, and for the correlation between independent tense interpretation and a de re construal of the relative clause. A theory of “past polarity”, based on traditional negative polarity theory, accounts both for the simultaneous “sequence of tense” construal of past tenses in subordinate clauses embedded within past tense contexts, and for the obligatory indexical/independent interpretation of present tense in a relative clause embedded within a past tense context. Combined with the copy theory of movement, the polarity theory also provides an account of the semantics of double access sentences, treating them as involving a special kind of reconstruction effect.