Sorry if this has already been explained. I'm new to this site/writing in general and I wasn't able to track down a similar thread.

My question is this: why do some syllables not agree when they're next to each other?

For example:
Your mom graduated Suma cum loudly up on dis dick

My issue with this is "graduated Suma", specifically how the "-ted" flows into the "Su-". I guess it sounds OK when read, but said out loud it feels like my tongue won't cooperate. If what I'm saying is relevant, is there a term for this? Perhaps i could be pointed to a list of syllables that agree and those that don't somewhere?

Any feedback is appreciated.