Jack Aitken wis born in Edinburgh, grew up in Bonnyrigg, Midlowden, an wis eddicate at Lasswade High School. He wis the auldest o three bairns o Adam Aitken, a miner, and his first wife Alexandrina Sutherland, wha dee’d whan Jack wis aboot nine. He tholed neglect as a step-bairn, bit his meenister, Rev. Oliver Dryer, halpit him to lea hame at the age o saxteen, an he ay stuck in at the schuil thanks tae a bursary. Bein the son o a miner, he got ither bursaries that alloued him to gang tae the University o Edinburgh in 1939. He ser'd in the Ryal Artillery durin Warld War II as a lance bombadier, an tane pairt in the Normandy landins an in the war in North Africa, risin tae the rank of sairgeant major. He wis commendit for bravery be Field-Marshall Montgomery in 1944. He graduatit MA with First Class Honours in English Language an Literature fae the Varsity o Edinburgh in 1947. In 1948 he wis appyntit Assistant tae Sir William Craigie, the Editor o the Dictionary of the Older Scottish Tongue (DOST) that is nou online as the Dictionar o the Scots Leid. He became Editor hissel whan Craigie retiret in 1956. Whan he tane ower editorial responsibeelity for DOST, Aitken pit in place a new readin programme that aboot dooblet the list of warks excerptit for the dictionar, correctin the bias taewart verse an leeterary prose. Aitken’s editorship begoud wi the letter J, an the impack o the new readin programme is tae the fore fae the thrid volume on.
Aitken wis ane o the first tae catch on tae the uisefuness o the computer for research in the Airts. Although computer methods kythed ower late tae be the wirkhorse o the collection process for DOST, he set up, wi ithers, the Older Scots Textual Archive, a computer-readable archive wi mair nor a million wirds o Aulder Scots leeterature.
For the maist o his career, up tae 1979, he combint his wark on DOST wi teaching, as a Lecturer an than a Reader in the Depairtment o English Language. He can be sayed tae hae creatit ‘Scots language’ as a univairsity subjeck. The haundoots that he screivit in the 1950s for his courses on the Scots leid wis for mony a year the only clear summaries o Scots vocabular, phonology, orthography, grammar an stylistics that existit, an they circulatit widely amang scholars. Ower time he made the maist o this material available in prent, and his writins is at the founs o the subjeck.
He wis Chairman o the Language Committee of the Association for Scottish Literary Studies 1971–1976; Chairman o the Forum for Research on the Languages of Scotland 1978–1981 an Honorary President fae 1994; Vice-President o the Scottish Text Society fae 1985; Honorary Preses o the Scots Leid Associe fae 1994; Honorary Vice-President o the Scottish National Dictionary Association fae 1995; an Honorary Vice-President o the Robert Henryson Society fae 1996. In 1981 the British Academy awardit him the Biennial Sir Israel Gollancz Prize. In 1983 he was awardit a DLitt be the Varsity o Edinburgh, an wis appyntit Honorary Professor in 1984. In 1987, he wis presentit wi a Festschrift: The Nuttis Schell, Essays on the Scots Language presented to A J Aitken.
Aitken is weel-kent for his formulation o the Scots Vouel Lenth Rule, kent as Aitken's Law forby. He developed a nummerin seestem for the Scots vouels that alloued a better unnerstaundin an descreeption o thair historical development.
He retirt in 1986 an dee’d at hame in Edinburgh on 11 February 1998 o ischaemia.