Apostrophes are used to indicate ownership with plural nouns, contractions and dates. Discover how the use of apostrophe changes when dealing with plural words with help from a certified tutor in this free video on punctuation in the English language. Expert: Paige Carrera Bio: Paige Carrera is a certified tutor for both Hillsborough and Pinellas Counties in the Tampa Bay area of Florida. Filmmaker: Christopher Rokosz