An interviewer from the Guardian once spent four hours recording Dame Thora Hird, who has died aged 91, stopping only because he ran out of tapes. “Listen to this,” he enthused afterwards, and turned up the sound of her singing a rude ditty about “balls” (rhymed with “orchestra stalls”) that she had written 60 years earlier. The journalist had interrogated Hollywood’s top brass across their studio desks, but they never fired him up as did this octagenarian in a wheelchair, talking about God and Morecambe Co-op.He was responding to a national institution, venerable yet rorty, both Queen Mum and a Donald McGill seaside postcard. She was 86 in the year of that interview, and had just won the second of her three Bafta awards as best television actress – this time for Alan Bennett’s Talking Heads monologue, Waiting For The Telegram, playing a centenarian who wept on remembering that she had not bedded her sweetheart the night before he left to die in the trenches.

Hird was not, she would sharply remind those who confused life and art, as old as the character – “It’s not actually me, love, it’s acting. That’s what I’m paid for, it’s pretending” – although she could just recall the first world war wounded convalescing in Morecambe. But then she could recall everything, even the names of her classmates at the Misses Nelson’s prep school: Vera Muff, Madge Peel, Ada Lob and Maudie Poles.

The Morecambe of Madge and Ada was home to Hird. Her dad, James Henry Hird, was manager of the Royalty theatre, and later of the entertainments on the pier, where a weekly ticket admitted holidaymakers to a pocket opera company and Madame Rosa Vere, who dived off in red tights every high tide, after which her mother passed the hat. Thora’s own mother, Mary, had carried her daughter on stage at eight weeks old; mam was acting a lass who had been done wrong by the squire’s son, and the bundled baby played the result. Theatre then was a reliable local business, like undertaking or clog repairs.

On leaving school, Hird worked for 10 years behind the Co-op cash desk, storing away the look of Mrs Edale, “who always sucked a split pea”, and Mrs Bradley, trying to feed 10 kids on nowt, and practised their mannerisms by night in the Royalty rep, while dad coached her timing and checked her inflections.

George Formby spotted her in 1939, wanted her to play his mother and sent up a casting director from Ealing Studios to peer through his monocle at her. She was too young for the role, but was put under film contract anyway -£10 a week between parts and £10 a day in work. They gave her a £5 note to cover the fare, and she arrived at the studios to the sound of the first air raid siren of the second world war.

Hird had sworn to her mam that she would, one day, wear a sequin-spangled frock, fur coat and orchids, and her mam had said she hoped it would keep fine for her; but on the wartime day when the beginnings of West End success financed a £50-fur, second-hand gown and slightly passé orchids, it poured down. She remained mindful of her dad’s exactitude about timing. The night before he died, he told her: “You’re a wonderful artist. I’ve lived to see you perform like you did tonight.”

Hird had her own family by then. In Morecambe, she had fancied James Scott, a drummer in the Winter Gardens orchestra, and they had courted decorously for four years, with him coming round to her mam’s for supper every night until they married in 1937 (the wedding photos were all teeth and arum lilies). They returned from honeymoon with 3s 8d left. He believed in her: “You will get on,” he said when they were broke, “and when you do, we’ll go round the world.” They laughed for an hour at that.

Scott put down £25 on the plot of land which eventually became their house at Prompt Corner, complete with the luxury of a built-in kitchen cabinet. He said he wished he could give Hird more on their first anniversary than a bunch of chrysanths, and she said, you can, you can give me a baby: in 1938, their daughter Janette pulled into the world, with fish servers in lieu of forceps. When Hird did get on, Scotty became her house-husband, cook and chaffeur, and manager to both Hird and Janette, who had a movie career as a child and teenage actor. Scotty served his war as a bedpan-wallah with the RAF – his wife’s description.

Through the 1950s in British cinema, Hird was one of the company of what you might call the Real National Theatre – actors always present because they represented the familiar and the true. On screen and stage, in more than 700 roles, she drew on those customers she had shelved in her memory at the Co-op. Until the 1960s, she was usually cast condescendingly – from a gawky maid named Eunice Sidebottom up to about middling dragon landlady. As she said later, she had not been at the front of the queue when the looks were given out, so she was always a character – yes, she played the nurse in Romeo And Juliet.

Yet she was John Osborne’s favourite actor – cast, at his request, in The Entertainer (1960) – both because of her ability to turn moods on a sixpence and because one of her specialities was Osborne’s pet hate, the narrow-minded mother-in-law with pretensions. Her best in that line was in John Schlesinger’s A Kind Of Loving (1962), with Alan Bates as her angry young son-in-law: Hird shoved in your face the power in that vernacular adjective “interfering”. She could do the dismissive mother of a floppy lad, too – Alan Bennett wrote her one in his television play Me, I’m Afraid of Virginia Woolf (1978), in which she tells him that being called Trevor is no bar to greatness; there had been a Trevor who had done well for himself in Northern Gas.

Hird was a natural for television. Long before her alliance with Bennett, there had been a clutch of amiable series: Meet The Wife; her matriarch of an undertaker’s family in In Loving Memory; The First Lady, in which her county councillor owed much to her own Auntie Nellie, who had hissed an aspirational “Yice” for “yes”, and never proffered a plate of biscuits ungraced by a doiley. What seemed eccentricity in her work was really extreme precision about the concerns of a local world. She set the tone of the women in The Last Of The Summer Wine.

Hird’s conversation shared with Bennett’s writing the exactly-placed names – a cup of Horlicks, a tumbler of dandelion and burdock – and a sense of a vast, lost innocence, of a world where knobbly knees were life’s norm. They also shared a certain humour – “Dear Thora, Just come up to change the lavatory seat, love Alan” read one of his postcards from Yorkshire – and a disdain for approximation: “That’s an ‘if’, not a ‘but’, and when you do a Bennett it is an ‘if’, not a ‘but’,” she remarked about memorising his scripts.

The first solo he created for her, A Cream Cracker Under The Settee, in the original Talking Heads series, won her first Bafta award in 1988. Her character faced a lonely death after a fall in the isolation of home. Bennett forced Hird towards her core toughness – no mawkishness permitted – as did Derec Longden in Lost For Words, his 1999 play about the last weeks of his mother’s life. “Do you want to be buried, mum, or cremated?” asks the son. “Oh, I don’t know, love,” Hird answers; then, after a pause timed to a nanosecond: “Surprise me.”

An easier side of her was visible for decades in television religious broadcasts, including her own series, Praise Be! Her chapel Christianity could come over comfy, although her relationship with “me pal oopstairs” clearly sustained her as the eventide fell. She used to say she had done a deal with him – no pain, when she was filming, in exchange for bearing whatever hurt when resting. Osteoarthritis demanded repeated hip replacements, she had a heart bypass and angina, and was immobilised after a kitchen fall too close to a Bennett script: “I was taking the little strings off the French beans, and I sat off the chair.”

After Scotty died of a stroke in 1994, Hird hired professional help, and worked on to pay their wages. There was still family, Janette and the grandchildren. It is a curious fact that her son-in-law was the singer Mel Torme (obituary, June 7 1999); she had visited the family in Beverly Hills 24 times – “It’s perfect for a holiday, but there’s no corner shop, love.”

Her autobiography, Scene And Hird, appeared in 1976. She was made an OBE in 1983, got an hon DLitt from Lancaster University in 1989, and became a dame in 1993. She met Princess Diana nine times and the Queen repeatedly, but it did not modify her memory of who she had been. “Never forget,” she told an awed reporter, “I scrubbed my mother’s steps when I was younger… Will you fetch me mink?”

· Thora Hird, actor, born May 28 1911; died March 15 2003