 Of the Swiss national languages (), 2,522 speak German, 2 people speak French, 8 people speak Italian, and 1 person speaks Romansh.The age distribution, , in Niederhelfenschwil is; 475 children or 18.3% of the population are between 0 and 9 years old and 406 teenagers or 15.6% are between 10 and 19.Of the adult population, 279 people or 10.7% of the population are between 20 and 29 years old.