The variation is amazing (though IIRC by the age of 5(? or thereabouts) you can't reliably tell the difference between the early talkers and the late) - at the other end of the scale from Img, my friend V has a little girl (J) who really didn't start talking at all until she was nearly three (she did a lot of baby-signing, and made distinct noises that V could understand, but very very few proper words let alone sentences). Kinda embarrassing when they came to visit and Img was running rings round J conversationally despite being 9 months younger but fortunately V wasn't worried & the two girls happily communicated in the universal toddler language of "running around going AAAAAHAHHHHHHH at each other". :-)