I 've often argued the case for shutting the National Portrait Gallery down, but until someone gets around to listening to me, you might as well see this spring's overlapping Constable and Gerhard Richter shows there ( www.npg.org.uk, 5 March to 14 June and 26 February to 17 May respectively). Portraiture is not really what Constable was about, but his pictures of kith and kin and the folk of Dedham Vale are bright as brass buttons even so. Whether it's useful to think of Richter's wonderful photo-based figure paintings as portraits is a matter for debate, but they have certainly been influential on younger artists such as Glenn Brown (pictured).
You can trace the connection in the one-man Brownfest at the Tate Liverpool ( www.tate.org.uk/liverpool, 20 February – 10 May), which finally gives Britain's pre-eminent copycat the recognition he deserves. Brown has not yet, so far as I know, set his meticulous squirrel-hair brush to The Hay Wain, but it can only be a matter of time. He will also doubtless be keeping a watchful eye on the National Gallery's Picasso: Challenging the Past ( www.nationalgallery.org.uk, 25 February to 9 June) which explores the Spaniard's own career as a copyist. Picasso turned out no fewer than 55 versions of Velázquez's Las Meninas alone, which may give Glenn Brown ideas for the future. Other of the Cubist's pickings include Poussin, Rembrandt, Goya, Delacroix, Manet and Cézanne.
Le Corbusier was a giant of Picasso's time and stature and, indeed, an admirer of Picasso. His own early training was as an artist rather than as an architect, and he sketched, painted and drew to the end of his life. His suggestion that Velazquez was "an ass" and that Picasso was the first painter since Goya to understand Spanish colour will no doubt have found favour at the Villa Californie. You can see Corb's painterliness in all its sub-Cubist glory at the Barbican Art Gallery this spring ( www.barbican.org.uk , 19 February to 24 May).
And if you have any energy left, you can totter across the river to that Corbusian echo, the South Bank Centre, to see the Annette Messager show at the Hayward gallery ( www.haywardgallery.org.uk, 4 March to 25 May). The French artist's tales of torture and abuse are scarcely cheery – think a mildly prettified Louise Bourgeois – but then who ever said that art had to be nice, eh?