All of those words describe the same concept but they are used slightly differently. "Quickly" is in its adverb form. This is the form you use to modify verbs (doing words). The adverb forms of hurry and rapid are hurriedly and rapidly. All of these words are basically the same. Hurry is a verb. It means "to do something quickly". For example "I hurried to the shops". The other two words can't be used this way. Hurry can also be used as a command. If you say "Hurry" to someone you are telling them to move faster. "Quick" can be used in the same way, but "rapid" can't be. Rapid is an adjective. This means it modifies a noun. For example, "The rapid dog ran at me". Quick can be used in the same way but hurry cannot. In summary: Quick: Adverb, verb, command, adjective Hurry: Verb, command Rapid: Adjective

Quickly = to do something with speed. I will answer this question quickly. Rapid = fast. It usually refers to objects, not people, although this is not a grammar rule, just the way it's used. So a rapid river is a river that moves very quickly. RapidLY means the same thing as quickly but is less commonly used. Quick (with no ly) means the same thing as rapid, and is more commonly used for people. Quickly is a manner of doing something, rapid is a manner of being. hurry is a word you use to tell someone to do something quickly. It needs to be done NOW, hurry! sometimes if you try to hard to do something quickly, then you mess up. HurriedLY = to do something fast, but sloppily.