Words that end in ILD

I had a student ask me about words that end  in I-L-D. Let's break it down. We have child,  

wild, mild. These all have the [aɪ] diphthong,  then Dark L.

To make the dark sound, the tongue tip stays down.

The Dark L is made with the back  part of the tongue pressing down and back. Child.  

Then the tongue tip can come up for the D. Child.  Wild. Mild.

But I-L-D can also be the [ɪ] vowel, like in build.

Same Dark L, tongue tip down.  Build. This is the same as the word guild,  

where it's [ɪ], Dark L, D, guild. 

Child, wild, mild, build, guild.