Linguistics was not a degree option when Dr Jim Feist first graduated from Auckland University 53 years ago.

But this week the university's oldest graduate picked up his doctorate in linguistics after completing his thesis within three years.

After a career of teaching, 74-year-old Dr Feist said he had enjoyed being on the other side of learning again.

He had not liked retirement so headed back to university to study the field he had always been interested in.

After two years studying a proficiency certificate in linguistics, he began writing his thesis - "The order of premodifiers in English nominal phrases" - on April 1, 2005 and handed it in on April 1, 2008, exactly the minimum three years it should take to write. Now his 93,000-word research sits "looking rather good in crimson with gold lettering on the bookshelf".

Dr Feist said he found the process rewarding.

"I would jump out of bed in the morning and think, 'Ah yes, I've got that thing to do today, oh good'.

"I was finding new ideas and explanations that people had not found before, and that's a very satisfying thing to do."

Dr Feist vows he will not stop investigating language any time soon - he cannot help but pick out interesting examples of language whenever he picks up a book or newspaper, and he will continue to add this research to the linguistics department's knowledge basket.

Dr Feist completed an MA in English from the university in 1955 and then taught English and French at various secondary schools. He was at Matamata College for 20 years.

He then taught English and Communication Studies at the old AIT, now Auckland University of Technology, before putting his teaching into practice and turning the instructions behind complex computer systems into layman's language for manuals.

His thesis draws on his past teaching and writing experience by looking at the rules behind language structures people inherently use, but do not necessarily understand.

But it has also opened his eyes to the digital world of research and the changing face of university, which he says is now "much more multicultural and much more varied".