I Fink it's Forsythia! But it Kould be Kerria!

I didn't have to go far for this shot as it's growing in a neighbour's front garden. I think it is Forsythia, in which case it was named in honour of Bruce Forsyth's great grandfather, William Forsyth who was something big in horticulture in the 18th Century.

Lots of people now saying it's a Kerria...