Question

Please explain adverb phrases, prepositional phrases, verb phrases, noun phrases and adjective phrases along with examples.
2) "How is the weather today, Sam?" said Jonh.
Why isn't a comma required before "said John?"

Answer 1

Look up and study each kind of phrase here:
http://www.chompchomp.com/terms.htm
The explanations and examples are excellent.

2) There's already a mark of punctuation after "Sam" -- there doesn't need to be a second one.