Separable and Inseparable.

108. Which ones are Separable?

Oi and Oy.

109. What is an Improper Diphthong?

The union of two vowels in a syllable, one of which is silent.

110. By what other name are they known?

Digraph.

111. How many Digraphs are there?

Twenty-five.

112. Name them.