A dialect, as rightly pointed out by Splash, is a regional variation of a language. Accent difference is only one aspect of dialect. Dialects differ from each other not merely in pronunciation or accent, but also in vocabulary, spelling and even grammar. For eg. British and American English are two different dialects of English that differ not only in pronunciation (eg. 'schedule'), but also spelling (eg.fulfil vs fulfill) and grammar (eg. 'different from' vs. 'different than').
From the Oxford Corpus of English:
PER ANNUM
For 30 years, it had gone remorselessly ahead, at about 80% per annum.
An Elan bond, where the bondholder can exercise the right to be repaid in 18 months, currently yields 19 per cent per annum.
With this fresh impetus, the total edible oil processing capacity, including vanaspati, is expected to cross 20 million tonne per annum.
PER YEAR
We can currently get about 5% per year from investing in long-dated gilts, so we might aim to get 6% per year from the property.
Penetration of digital has hit 20 % in a year, with incremental revenue per subscriber at $22 per year and growing, he said.
This still leaves teachers $3,000 per year short of accountants, $17,000 short of computer systems analysts, and $25,000 short of engineers.
These example sentences are representative of the most common uses of these two phrases and, as one can see, there is no real difference between per annum and per year in usage.
As kiamlaluno says, per annum is traditionally used more in financial contexts than per year, but these sentences show that per year is also perfectly acceptable.
Best Answer
Technique is the standard spelling. Technic is a variant, for example used for trade names such as by Lego and Panasonic and may sometimes be pronounced with a shorter unstressed i.