That seemingly small feat of phonetic genius earned him first place in the Illawarra regional final of the NSW Premier's Spelling Bee competition at Unanderra Public School on Monday.

However, the real marvel is that the 10-year-old Pleasant Heights Public School word wizard could not understand or speak English when he first moved to Australia from Argentina four years ago. He will now contest the state final in Sydney this November.

The Year 5 student said he loved spelling and the shape of words just came naturally to him .

"When I am spelling a word out loud, I always close my eyes and picture it written on a huge banner and each of the letters flashes when I say them - that really helps me," he said.

His father, Gerardo, said he was ecstatic when his son out-spelled his predominantly older competition to win the final and that Tadi's hard work in the lead-up to the regional competition had paid off.

"We had a lot of help from our neighbours and friends, who helped us pronounce the words that I did not know," he said.

"It is just amazing ... when we arrived here Tadi used to cry at school because he did not know what people were saying. Now he hopes to go to Smith's Hill High School."

Charlie Gonzalez, from Barrack Heights Public School, won the junior section in the Illawarra final.