Quick answer
ie and üe glide into a short ‘e’; er is a single curled-tongue final unlike anything in the others.
ie
üe
er
Hear each sound, then repeat it aloud.
When to use it
For ie and üe, start on the first sound and glide into a light ‘e’. For er
, relax the tongue and curl it slightly.
Common mistake
er
is one sound, not ‘e’ + ‘r’ said separately. Let the tongue curl while you say the vowel.
Practise aloud
谢 thanks
月 moon
二 two
You’ve got this!
er stands apart from the other finals — practise it on its own. You already meet it in èr (two). Then glide through ie and üe as in xiè (thanks) and yuè (moon).