I've never seen a bullfinch, Pyrrhula pyrrhula, in my garden (I've lived here 33 years). They may be common in other places but I've have hardly ever seen one, and I'm pretty rubbish at bird identification anyway. I assumed bullfinches look like these. But of course those are just the brightly coloured males. So when two birds turned up, one with distinct markings and the other rather drab, I thought at first they were a male and female of I knew not what. And then I realised. This was no pair but a mother and child, a female and juvenile bullfinch. There are pictures showing the difference on the BTO website. And lots of other information.