It’s time for the SECRET of /ɚ/.
The Secret: written r is pronounced /ɚ/.
For the /ɚ/ sound,
pull your tongue all the way to the back of your mouth.
Let’s listen to these 1-syllable words with written vowel i.
Notice that these words are all spelled with i … pronounced /ɪ/.
Now, let’s hear what happens when a word is written with a vowel i + r.
dirt /dɚt/… dirty /dɚ-diy/
These words are all pronounced /ɚ/… so, spelling i + r is pronounced /ɚ/.
dirt /dɚt/ … dirty /dɚ-diy/
Sir /sɚr/ Winston Churchill
Note: There are various symbols that can represent written r, as you can see here:
stressed r = /ɝ/ or /ɜr/ or /ɚ/
unstressed r = /ər/ or /ɚ/
To avoid confusion, I use only one symbol throughout the blog: /ɚ/