Y2 DS's teacher asked me if we'd been teaching him about punctuation. I said not especially no, just answering questions about exclamation marks etc. she then went on to say that he's using brackets and colons correctly in his written work without having been taught it. I asked him how he knew how to use them and he said he'd seen his teacher use them in power points etc and worked out what they were for. He seems to see or be told something once and he knows how to use it.