Listen closely to how some Californians talk and you’ll hear it. The T sound in words like “water” or “accent” can soften or disappear. “Water” becomes “wader.” “Mountain” turns into “moun-in.” Even “winter” can sound like “winner.” They are small changes. Easy to miss. But linguists say those subtle patterns are part of something bigger. California does have an accent — and it may have helped shape the way much of the country speaks today. For decades, pop culture has had a very specific idea of how Californians sound. “Valley Girl” stars Nicolas Cage and Deborah Foreman (c) Atlantic Releasing/courtesy Everett Collection ©Atlantic Releasing Corp / Everett Collection “Clueless” stars Stacey Dash and Alicia Silverstone (c) Paramount/courtesy Everett Collection ©Paramount/Courtesy Everett Collection In 1982, Moon Zappa introduced her “ Valley Girl ” character from the song of the same name alongside her father, musician Frank Zappa, on “Late Night with David Letterman.” The exaggerated speech pattern quickly…