something about english pronunciation?

You must clearly pronounce the full word with the "t" on the end...then clearly pronounce the "t" of the next word.
I can't think of an examples where you can run two English words into each other.
Each word should be pronounced separately and precisely.
Many people "murder" the English language, and I don't mean people who have English as their second or third language...I referring to some people who were brought up with English as their only language!

EDIT..EDIT..."hamburger" is correct with the example he/she used ..some people do run those two "n"s together......but that is not good English.

I am no professor of english but I think it would be proper to pronounce each word clearly as per phonetics and which syllables to put the stress on.

First, this is a bad example, because there is a difference in the English pronunciation of the single "t" and the "th" sound. For this reason, there would be some distinction between the two sounds.

A better example would be "n." Here is a sample sentence: "He can negotiate the agreement." In this case, a native speaker would blend the two "n's" together.

You need to pronounce both sounds clearly. Because 't' and 'th' are not the same sounds.
"which meant that"

If they have the same pronunciation, you can run them together.
"I don't know" sounds like "I dunno"

Technically you should pronounce both Ts, but I don't think people will catch it if you don't.

It may sound like people leave off the t because people tend to get lazy with their speech and cut corners. The correct way is to pronounce the syllable and make sure there is a clear space between the words so they don't run together.