Theory:
Parts Of Speech
Words are the smallest unit of the English language, and depending on the work they do, they can be put into one of eight major groups called Parts of Speech.
These 8 major parts of speech are:
Nouns
Verbs
Adjectives
Adverbs
Pronouns
Prepositions
Conjunctions
Interjections
and each one has several different kinds.
It is extremely important that you familiarise yourself with these different parts of speech, because they are represent the most fundamental concepts of grammar. An in-depth knowledge of this topic will not only make you a better writer, but an effective communicator as well.
All grammar functions depend on these groups and knowing the difference between them is of fundamental importance for the Cambridge exams.
The same word can be more than one part of speech, depending on the context of the way it is used.
Parts of speech can have different names, like modifiers and discourse markers, but the actual names are not that important, as long as you understand what they do, and learn to use them correctly and effectively.