[iy] and [i]

[iy]	[iy] is articulated with the front of the tongue raised close to the roof of the mouth. The lips are spread and close together, as if smiling. [iy] is sligthly diphthongized.
[i]	The articulation of [i] is similar to that of [iy], except that the lips are not spread so wide. The tongue is a little lower, too.

Minimal Pairs

PLAY	This kid eats peas and sips milk.
PLAY	Silly sheep weep and sleep on this hill.
PLAY	Six sick slick slim sheep leap across the pit.
PLAY	Jim drinks bitter beer and cheap fizzy drinks.
PLAY	I slit the sheet, the sheet I slit, and on the slitted sheet I sit.
PLAY	Six thick thistle sticks are sitting on this big window sill.