When 'S' Secretly Turns Into a 'Z'

In Greek, the letter for 's' generally stays a crisp, voiceless sound no matter what follows it. English is sneakier: the letter 's' often turns into a full 'z' sound depending on what's next to it, and spelling gives no clue. Say 'dogs,' 'cars,' or 'is' out loud — every one of those final S's is actually pronounced as a 'z,' even though the letter never changes. This happens because English likes its sounds to match in voicing, so an S after a voiced sound like 'g,' 'r,' or a vowel gets pulled toward voicing too. Try this: say 'cats' and 'dogs' back to back, placing two fingers on your throat. You should feel no vibration on the final sound of 'cats,' but a clear buzz on 'dogs.' Practice a short list — 'books,' 'trees,' 'cups,' 'pens' — checking the buzz each time. It's a quiet rule, but hearing it will sharpen your ear for natural English.