also shakespeare is incredibly specific. the example I like to use is the famous

"Friends, Romans, Countrymen, Lend me your ears!"

Which takes place in a crowded marketplace.

Count the syllables: 1 (friends), 2, (romans), 3 (countrymen), 4 (lend me your ears)

it's a line in which the meter matches the intent - attracting attention in a big group.

Bill will also often add an eleventh unstressed syllable to his dialogue lines if he wants a character to seem vulnerable or weak, indicating they have fallen off meter because of their inner thoughts

very occasionally he does an eleventh STRESSED syllable when a character is being especially dominating and murderous.

The other famous examples is when a peasant or very low status character speaks, it won't be in verse at all, but plain prose.