When is an exhibition not an exhibition?

VISUAL ART: PortmanteauKevin Kavanagh, Chancery Lane, Dublin Until May 8; The Place of MemoryRua Red, South Dublin Arts Centre (beside the last stop on the Red Luas line) Until May 22; Black TearsTaylor Galleries, 16 Kildare St, Dublin Until May 8

IS IT AN exhibition? Tadhg McSweeney’s Portmanteau, at the Kevin Kavanagh Gallery, certainly looks like an exhibition, and in the case of one work it even sounds like an exhibition, but in the sense that it comes across as a full-scale, working model of an exhibition.

True, there are paintings on the wall, and several sculptural pieces distributed throughout the space, but when you look more carefully at any of them you’re likely to become less sure about what you’re looking at. What does become clear is that McSweeney loves the flicker between certainty and uncertainty.

He likes making things that invite recognition and then cancel the invitation at the last minute. This isn’t something new for him. From his first solo show in 2004 he’s given the impression of being an artist who was looking at the possibility of pursuing a certain mainstream artistic path, with the standard outside pressures, but quickly decided that he must instead find his own way.

His work is not exactly a rejection of what has gone before, of artistic or aesthetic conventions, but a bid to figure out how one can make something with the remains, the residue of what has gone before.

It's as if he asks himself whether it's possible to do something with an exhausted tradition and, perhaps more to the point, with a set of assumptions and values that have let us down. He often deals literally with off-cuts and discards, and is taken by chance resemblances – as in the sculptural Head, which boasts a found classical profile.

As the detailed catalogue note observes: “Many of the paintings appear to arise out of a conflict between chaotic landscape and the artist’s need to draw forth a narrative or theme”. More accurately, perhaps, one could say that a chaotic landscape, coherently expressed, would in itself be an accessible narrative. But McSweeney offers some constituents of landscape painting and then veers off in another direction entirely, forestalling us just as we are about to settle into reading a landscape in an habitual way.

Similarly his frames, which are a complete strand of his work in themselves, are ingenious contrivances that play with the idea of being frames without quite committing. Look at one of his paintings and you're left with the sense that you're simultaneously looking at a prototype for a possible painting. If that sounds a bit contrived, it is not in actuality. McSweeney has a deft, ingenious touch with forms, materials, images and lighting. Some of his sculptures are constructed as miniature theatre sets. Enclosureis an elegantly witty account of a tank containing lizards. The kinetic Breatheis a remarkable, DIY version of a lung, rasping away laboriously. There's a whole museum crammed into his portmanteau. Don't miss it.

Gaetano Tranchino's paintings in The Place of Memoryat RUA Red Gallery in Tallaght, have a dreamy, magical quality to them. They are pictorial fables, opening up a narrative space that is warm and nostalgic without being at all overly sweet. There is a distinctly Mediterranean feeling to the world they evoke, which is hardly surprising given that Tranchino is from Syracuse on the south-eastern coast of Sicily, a place steeped in classical history.

In his work it’s a beautiful realm. Recurrent motifs include the lush, well tended garden, the comfortable, accommodating house, remnants of antiquity in the form of stone carvings or pillars, the road and the gate, the sea and the land. All of these elements frame accounts of arrivals and departures, via bicycle, car and sailing boat or liner. Our view of events is usually oblique and fragmentary: we glimpse a bicycle rounding a corner, the hind quarters of a dog, its tail wagging, a car making its way through the night, a ship pulling away from the dock. A man stands, hands in pockets, looking into the evening light, as though awaiting someone.

The curvilinear shapes suggest travel. Most of what we see, including ships and cars, has a retrospective look. The work invites comparison with that of Simon English, who seems to share many of Tranchino’s concerns. But while English likes drastically toned down colours and modulated shades of grey, Tranchino embraces colour with all the verve of David Hockney.

He uses intense yellows, pinks, reds, greens and blues in richly textured, jewel-like masses, often accentuated by strong tonal contrasts. If he wasn’t such a good painter it could all go horribly wrong, but he is actually a fine, sensitive painter, and the paintings are not only attractive but capable of withstanding sustained attention: they’d be good to live with, in other words. Tranchino’s place of memory is tinged with the sadness of loss, but as formulated, it’s an almost pleasurable sadness.

Not much pleasure is inferred in Cecily Brennan's intense Taylor Gallery exhibition Black Tears. The show consists of a series of delicate, finely made watercolours, all close-up views of the face of a crying woman; two large-scale charcoal drawings in which a figure is enveloped in a black cloud; another in which a figure is left drained and exhausted; and a projected video work, from which the show takes its title, in which a woman sobs, apparently uncontrollably. There's a certain insistence involved in the sheer repetition of image and action, as though we're being reminded to keep our minds on the issue.

The issue is the helpless fall into bleak, limitless depression, a state of melancholia and this is an attempt to convey what it is like. Two of the charcoal drawings cite a line from the last work of the British playwright Sarah Kane, 4.54 Psychosis, an exploration of a state of suicidal depression, first performed after Kane's own suicide in 1999. Brennan's show is tough and unflinching, though the hardness of the high-definition, hard-lit video, and the force of the charcoal drawings is contrasted effectively with the tenderness of the watercolours.