Jack Aitken wis born in Edinburgh, grew up in Bonnyrigg, Midlowden, an wis eddicate at Lasswade High School. Efter serrin in the Ryal Artillery durin Warld War ll, he retoured tae the Varsity o Edinburgh tae continue his teachin career an tae resairch the oreegins o the Scots an Celtic leids.
He helpit Sir William Craigie in the compilation o "The Scottish National Dictionary" an "The Dictionary of the Older Scottish Tongue", that is nou online as the Dictionar o the Scots Leid. Efter Craigie, he teuk ower the The Dictionary of the Older Scottish Tongue as editor an feenished the first o thaim in 1976. Aitken speired oot a new readin programme o auncient manuscripts an historic papers an aw, for tae increase the reach an richtness o the dictionar. Upo feenishin in 2000 the dictionar wis dedicate tae him.
Aitken is weel-kent for his formulation o the Scots Vouel Lenth Rule an aw, kent as Aitken's Law forby. He developed a nummerin seestem for the Scots vouels that alloued a better unnerstaundin an descreeption o the historical development o thaim an aw.