| in a pig's patoot | | | |
| in a pinch | | | |
| in a rut | | | |
| in a snap | | | |
| in a walk | | | |
| in bad odor | | | |
| in bed | | | |
| in black and white | | | |
| inch along | | | |
| in character | | | |
| inch by inch | | | |
| inch forward | | | |
| inch up | | | |
| inchworm | | | |
| in concert | | | |
| in control | | | |
| Indian sign | | | |
| in diapers | | | |
| in droves | | | |
| in Dutch | | | |
| I never miss | | | |
| in every sense of the word | | | |
| in fighting trim | | | |
| in focus | | | |
| in for a penny, in for a pound | | | |
| in for it | | | |
| in full force | | | |
| in full gear | | | |
| in harness | | | |
| in heaven's name | | | |
| in hot pursuit | | | |
| in jest | | | |
| in kind | | | |
| in layman's terms | | | |
| in light of | | | |
| in line | | | |
| inner ear | | | |
| inner strength | | | |
| in nothing flat | | | |
| in no time | | | |
| in on | | | |
| in one bite | | | |
| in one's altitudes | | | |
| in one's back pocket | | | |
| in one's cups | | | |
| in one's dreams | | | |
| in one's own good time | | | |
| in one's own little way | | | |
| in one's wildest dreams | | | |
| in order | | | |
| in pampers | | | |
| in plain sight | | | |
| in reaction | | | |
| in recent memory | | | |
| in safe hands | | | |
| ins and outs | | | |
| in short trousers | | | |
| inside baseball | | | |
| inside out | | | |
| inside scoop | | | |
| in someone's face | | | |
| in someone's pocket | | | |
| in spades | | | |
| in spite of | | | |
| installed base | | | |
| in stitches | | | |
| interpret away | | | |
| in the act | | | |
| in the black | | | |
| in the blink of an eye | | | |
| in the business of | | | |
| in the can | | | |
| in the dock | | | |
| in the driving seat | | | |
| in the flower of one's youth | | | |
| in the green tree … in the dry | | | |
| in the hopper | | | |
| in the know | | | |
| in the line of duty | | | |
| in the making | | | |
| in the offing | | | |
| in the raw | | | |
| in the right place at the right time | | | |
| in the same boat | | | |
| in the snap of one's fingers | | | |
| in the stratosphere | | | |
| in the tank | | | |
| in the trenches | | | |
| in the way of | | | |
| in the world | | | |
| in this day and age | | | |
| in token of | | | |
| into thin air | | | |
| in two shakes of a lamb's tail | | | |
| invited to the cookout | | | |
| in your dreams | | | |
| iron fist | | | |
| I see, said the blind man | | | |
| itch the ditch | | | |
| I tell you | | | |