Further to intonation, this innocent sentence, subject of analysis from several linguists, illustrates the importance of stress in English:

The Queen said she was glad to be in Manchester, and then the Duke made a joke.

To spell it out, if the two components are unrelated, then the stress would be on joke; but more entertaingly, if you place the stress on Duke, then you imply that the Queen was joking when she said she was glad to be in Manchester, with the Duke following up with a quip of his own.