My DD is almost 4 and has been recognizing some words since she was...maybe 2? Definitely stop, go, Mama, her name, some random others. Now, at nearly 4, she recognizes a fair number of words but isn't reading.
When she was 2 and saying "Look mama, S, T, O, P, spells Stop!" or when she would see her name in print and recognize it, it was one of many little ways I knew she was different...but now that she is 4, I don't really consider the list of words she reads extraordinary at all. She was quite early with her alphabet (reciting and reading the letters) but it seems to be that it is more that she has an amazing memory, not that she was destined to be an early reader.
So,IMO. if he was recognizing words like his name, stop etc at 2.5....it may be a sign he's advanced? Not as clear a sign as if he were recognizing more complex words or words without the association of the red sign, ykwim? But it certainly is fun when you're on the bus and your tiny person is reading signs out the window and people do a double take, haha! But I really have no idea, that's just my guess.
Also, DD is my oldest and has been pretty obviously different/ahead from birth, so I don't even know anymore what "typical" looks like, you know? Maybe it is actually rare that kids can read a few words at 2? my perception of normal is all screwed up. See above where I have decided i't's too late for my almost 4 year old to be an early reader, because she hasn't started yet, hahaha. My idea of early is 2 or 3, having read this board!
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