The difficult part here is the “cluster” or group of consonants at the end of “wouldn’t”, but don’t panic! The l is silent – hurrah! One problem solved. Most people just miss out the t completely, and suddenly it’s much easier. Practise going from /d/ to /n/ without making a vowel in between. This means you have to keep the front of your tongue touching the ridge behind your teeth.
We say this when something annoying happens, for example, you wanted to go to the beach, but when you look out of the window, it’s raining.