Is considered adjective in the below sentence? If it is adjective, why is it adjective?
That could be considered 'best practice'.
Is considered adjective in the below sentence? If it is adjective, why is it adjective?
That could be considered 'best practice'.
Not in this context.
"Consider" is a verb. It means to think carefully about something. Some verbs can be used as adjectives in the past tense, for example:
The toast was cold and burnt.
"Cold" is an adjective, because it is a property of the toast. "Burnt" is something that happened to the toast in the past, but it also describes the toast's condition now.
Likewise, "considered" could be used to describe a decision, for example:
It was a carefully considered decision.
This is adding detail to the description of a decision that has already been made by describing it as having been carefully considered.
However, I do not think this is the case in your example.
That could be considered 'best practice'.
"Best practice" usually refers to a framework of ideas or methods that are generally agreed as the best way of doing a job or task. In most fields, what actually constitutes "best practice" is subject to change, and not always strictly adhered to.
I read your example as saying that whatever preceded the statement could be thought of, or considered as being "best practice". It is encouraging you to think of it that way, and as such is an action, and a verb.