The word adverb is derived from the Latin ad meaning added to and verbum.
Adverbs are those words which are added to verbs, adjectives, or other adverbs.

Adverbs denote:

• time
• place
• manner
• quality

A preposition is a word used to show the relation between a noun or a pronoun and some other word or phrase.

For example

The words from, upon, on, and with in their normal use are prepositions.

The prepositions are an indeclinable class; that is, each preposition has only a single form.
In addition, the class of prepositions is a closed class because new prepositions are not being added to the language. Prepositions are a small group of words used to denote the relations of place, time, cause, manner, property, or quality.

The word preposition comes from the Latin prae meaning before and positio meaning a placing, thus a placing before. A preposition is commonly placed before the object with which it is associated.

A conjunction is a word used to connect words, sentences, or the parts of sentences.

For example

The words and, but, since, because, and or in their normal use are conjunctions.

The conjunctions are an indeclinable class; that is, each conjunction has only a single form. In addition, the class of conjunctions is a closed class because new conjunctions are not being added to the language
Conjunctions are a small number of words used to join the parts of a sentence.

The name conjunction is derived from the Latin conjunctus meaning joined together.

An interjection is a word that expresses some strong or sudden emotion of the mind.

For example

The words 0, shucks, and alas in their normal use are interjections. Most profanity can be classified as interjections.

The interjections are an indeclinable class; that is, each interjection has only a single form. The class of interjections is a not a closed class. New interjections are constantly being added to at least the informal language.
The word interjection comes from the Latin interjectus meaning thrown between. Interjections are a few words that do not enter into the structure of a sentence, but are thrown in at pleasure.