Yes — "once" is a First Grade sight word. It's pronounced "wuns", which doesn't clearly follow from its unusual "o-n-c-e" spelling, so it's memorized rather than sounded out.
Once upon a time, there was a little girl.
"Once" is famous as the opening word of countless fairy tales ("once upon a time"), which makes it one of the earliest irregular words many children encounter. Its spelling gives few reliable clues to its actual pronunciation, making whole-word memorization the most practical approach.
Since "once" is so strongly linked to "once upon a time", use that familiar story-opening phrase to anchor the word firmly in memory.
Word Wizard teaches "once" with Flash Cards, Listen & Pick, Spell It, and Write It — four game modes that turn repetition into play.
See "once" with its picture, syllables, and example sentence — with native audio.
Hear "once" spoken aloud and pick it out from similar-looking words.
Build "once" letter by letter from shuffled tiles.
Word Wizard turns sight word practice into a game — Flash Cards, Listen & Pick, Spell It and Write It, from Pre-K through Grade 5.