Breakdown:
1. Wow! – Interjection
2. The – Article (Adjective)
3. happy – Adjective
4. dog – Noun
5. quickly – Adverb
6. ran – Verb
7. under – Preposition
8. the – Article
9. table – Noun
10. and – Conjunction
11. he – Pronoun
12. barked – Verb
13. loudly – Adverb