DIPHTHONGS BEGINNING WITH I.
I, in the situation last described, readily coalesces with the vowel which follows, and is often sunk into the same syllable, forming a proper diphthong: as in fustian, quotient, question. The terminations cion, sion, and tion, are generally pronounced shun; and cious and tious are pronounced shus.
Ie is commonly an improper diphthong. Ie in die, hie, lie, pie, tie, vie, and their derivatives, has the sound of open i. Ie in words from the French, (as cap-a-pie, ecurie, grenadier, siege, bier,) has the sound of open e. So, generally, in the middle of English roots; as in chief, grief, thief; but, in sieve, it has the sound of close or short i. In friend, and its derivatives or compounds, it takes the sound of close e.