Commonly diff words In English start on letter I
and How to Use Them

intentness-earnest, earnest infected, sore intraspecific, specific inactive, latent iupac, propylene interesting, ponderable immobilize, petrify interweave, entangle iso, drug indulge, laugh isolated, neosilicate interbreeding, sympatry isomer, naphthoquinone indentation, prick inconsistency, inconvenient interject, interjection infants, neonatology impure, faints inviting, invitational impoverish, pauperize irregular, ragtag immoblized, paralyzed intrigue, plod impatience, please illinium, promethium insufficient, scanty