used to
useta
/ˈjuːstə/ReductionElisionAssimilation
In real speech
What happens to the sounds
The d in used disappears before t, and to weakens to /tə/: used to → “YOOS-ta”.
When to use it
Past habits: I used to smoke. Don't mix it up with be used to (= be accustomed to).
Casual → formal
Slang
useta
Neutral
used to
Formal
previously / formerly
Sound notes
Reduction: unstressed words get squeezed, and their vowels turn into the neutral sound /ə/.