<p><strong>Adverb:</strong></p><ul><li>from then till now (often preceded by ever): He was elected in 1978 and has been president ever since.</li><li>between a particular past time and the present; subsequently: She at first refused, but has since consented.</li><li>before now; ago: long since.</li></ul><p><strong>Preposition:</strong></p><ul><li>continuously from or counting from: It has been warm since noon.</li><li>between a past time or event and the present: There have been many changes since the war.</li></ul><p><strong>Conjunction:</strong></p><ul><li>in the period following the time when: He has written once since he left.</li><li>continuously from or counting from the time when: He has been busy since he came.</li><li>because; inasmuch as: Since you're already here, you might as well stay.</li></ul><p><strong>End of Response</strong></p>