When reading ESL teachers' blogs I sometimes come upon as instruction like - 'tell about something that happened to you this week'. Now that doesn't sound quite right to me; I expect to read 'tell me' or 'tell us' about something. Without a personal object, I'd expect 'talk about something that happened to you this week'.
At first, I thought this was because the teachers weren't native speakers, but then I noticed a couple of examples from American writers, so I thought I'd have a bit of a closer look