لخّصلي

The subject does not really perform an action, nor does the verb describe a mere state of being.If we broaden our definition to say that a verb tells us something about some person or thing, it becomes difficult to explain the difference between verbs and adjectives.These definitions may cover the recognized situations acceptably, but any definition that covers all cases becomes so vague as to be useless for making discriminations.The traditional definitions of parts of speech are misleading as they look for semantic definitions.The Linguistic View Given this confusion over the concept of parts of speech, it's reasonable to ask if we can just abandon the concept completely.In fact, the problems with traditional parts of speech have prompted some linguists to abandon the term part of speech completely.

The subject does not really perform an action, nor does the verb describe a mere state
of being. It actually describes a change of state. If we broaden our definition to say
that a verb tells us something about some person or thing, it becomes difficult to
explain the difference between verbs and adjectives.
The traditional definitions of parts of speech are misleading as they look for semantic
definitions. These definitions may cover the recognized situations acceptably, but any
definition that covers all cases becomes so vague as to be useless for making
discriminations.
The Linguistic View
Given this confusion over the concept of parts of speech, it’s reasonable to
ask if we can just abandon the concept completely. Why do we really need to
know what a noun is? In fact, the problems with traditional parts of speech
have prompted some linguists to abandon the term part of speech
completely. They have not, however, given up on the idea behind the
label. The term part of speech simply means “a word category.” In other
words, it reflects the important observation that words can be grouped into
categories because they behave similarly. For example, consider how we can
complete the following sentence frames:
(4) She has no ____.
(5) She can ____.
The first sentence can be completed with words like bicycle, shoes, worries,
ability, home, etc., that is, with nouns, but not with words like went, happy,
in, or cheerfully (verb, adjective, preposition, and adverb respectively).
The second sentence works with words such as hide, fly, delay, lie, cry, etc.
(verbs), but not shoes, beautiful, happily, into, etc.