Miro "took the line for a walk" to create his art.

Welsh language poet Menna Elfyn takes her words to the well and there, through the alchemy of craft, the liquid phrases become sharp-edged diamond-poetry. She no longer "makes" English versions of her own poems, so in this significant collection of new poems she works with six close readers of her work who become interpreters rather than mere translators.

In the title poem, the Welsh "mur-mur" becomes "wall-wall" and continues "walls are sounds/ of the old tongue./ We understand 'shibboleth',/ the 's' is clear on our lips;/ the 'sh','sh','sh',/ a warning that it's the language of silence." Then, with the quirky humour that both punctuates and propels her best work, she quotes in English a leaflet issued by the National Heart, Lung And Blood Institute: "Although you may have an innocent murmur throughout your life you won't need treatment for it." Then the poem concludes: "Poets live with beats,/ consistently irregular;/ lubb-dupp, its melody/ carries a pitch that flows/ through all the heartaches/ and metre of the blood."

Throughout this slim but significant collection, her fifth, there is an awareness, indeed a sad acceptance, of bereavement as linguistic emptiness, but it is countered by a determination that the language is not and cannot be silenced. In the magnificent The Wasp Inspector, wasps "crave the human touch", they "insist on soliloquies"; the poem concludes "'be still', we sigh,/ is it not enough you pass/ the muse by - the sting of the song?"

The most personal and moving works lie in a sequence of 17 poems inspired by the imprisonment of Catrin Glyndwr (daughter of the great Owain) in the Tower of London with her three children for years before they die mysteriously. In Arrival there is "through the walls/ one murmur/ merriment and mayhem". After that only "mayhem" rules. Even when they sing together "like birds/ the mountain curlew, the bold robin,/ the starlings, hungry and fearless". To no avail. At the end "a crowd came to gaze at us./ I bade the children be dumb,/ deceived them they might let us go." A necessary deception when mother tongue is being threatened. Empathetically Elfyn quotes Thoreau: "I sing of the telegraph harp." So we hear her songs, urgent and demanding as all good poets' work must aspire to be.

Despite her unwillingness to translate her own poems into English, Elfyn, in a coda to this collection, includes three bilingual versions of her fellow political activist, the Quaker Waldo Williams (1904-1971). His poems survive simply because friends collected and published them after his death. In a dedicatory poem Heb/Without, Elfyn refers to him as "my childhood garden's Socrates". Reading his work aloud to myself was to be reminded it has been far too long since Elfyn herself appeared in Scotland. Let that be remedied. We need to hear this most international of commentators give us her own particular Celtic message.

American Adrienne Rich (1929-2012) was a confrontational rather than confessional poet during the last 30 or so years of her life. A simplistic reading of her later work, badly served by this posthumous collection, presumed she gave misandry poetic expression. However this mother of three sons, who discovered her true sexuality later in life, always seemed to me to be a humane excavator of the complex choices offered to and accepted by humans irrespective of gender. "I am she: I am he/ whose drowned face sleeps with open eyes." I will miss the probing phrases that exposed common vulnerabilities in poems of beauty and tenderness.

John Fuller's New Selected Poems 1983-2008 is a companion to Selected Poems 1954-1982. One hopes in the near future to see a comprehensive Collected Poems to replace the out-of-print 1996 volume. Reviewing the latter in these pages I noted the poet's ability to contain emotion while concealing intimacy: "Wrestling the challenge of Infinity/ To Personality". The later work shows Fuller continues to be a reliable social commentator who has the wit not to need malice.

Murmur

Menna Elfyn

Bloodaxe, £9.95

Tonight no poetry will serve: Poems 2007-2010

Adrienne Rich

Norton, £9.99

New Selected Poems 1983–2008

John Fuller

Chatto & Windus, £15.99