Sentence 1: "Interjections tell emotion or surprise. "
Nouns: interjections, emotion, surprise.
Verb: tell.
Preposition: or.
Sentence 2: "I didn't know that it is considered as a thing in parts of speech."
Nouns: thing, parts, speech.
Verbs: didn't know, is considered.
Pronouns: I, it.
Prepositions: as, in, of.
Conjuction: that.
Article: a.