Yes — "on" is a Dolch Primer sight word. It follows regular phonics rules, but it's taught for instant, automatic recognition because it appears so often in early reading.
The book is on the table.
"On" is phonetically regular, but as one of the most common prepositions in English it needs to be read automatically, not decoded, for a sentence to make sense at a normal reading pace.
Practice "on" alongside "in" and "at" — the three most common position words — using real objects around the house.
Word Wizard teaches "on" with Flash Cards, Listen & Pick, Spell It, and Write It — four game modes that turn repetition into play.
See "on" with its picture, syllables, and example sentence — with native audio.
Hear "on" spoken aloud and pick it out from similar-looking words.
Build "on" 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.