/nd/ 变成 /m/

first the /d/ disappears in between two consonants. You might remember this from our video on elision. So 'sandwich' becomes 'sanwich'.

Now, we have an /n/ followed by a /w/ and /n/ changes to /m/ before /w/. So sandwich becomes samwich.

1. My grandparents have been married for 50 years.

2. I got a standby ticket.

3. The band played until midnight.

4. I left my handbag on the train. 

5. It was hand made.

详见： https://www.bbc.co.uk/learningenglish/english/features/pronunciation/tims-pronunciation-workshop-ep-10