 Of the Swiss national languages (), 1,334 speak German, 9 people speak French, 6 people speak Italian, and 2 people speak Romansh.The age distribution, , in Oberhelfenschwil is; 253 children or 17.4% of the population are between 0 and 9 years old and 239 teenagers or 16.4% are between 10 and 19.Of the adult population, 136 people or 9.3% of the population are between 20 and 29 years old.