Whether the following sentence is correct?

It would be a good idea if we (or Admin) could move discussions to an appropriate Interest. Unfortunately, I gather that this is nowhere as simple as deleting a discussion or removing inappropriate tags! There is already an Interest "English". Now there is one for "English Language" as well.

sir Whether the word police is singular or plural, I can see in some of the newspaper the word police is considered plural. What is the truth about the word?

Police is a collective noun and is treated as a plural. "The police are making arrests." Individuals are usually referred to as 'members of the police force', 'policemen/women': "A policeman called to see me today.", "A few members of the police force/police men and women were in the crowd." (but you might also hear - incorrectly - "A few police were in the crowd") The word 'police' can serve as a noun, an adjective or a verb. "The case was investigated by the police" (noun) "The man was taken into police custody. Three policemen were needed to restrain him" (adjectives) "The security firm agreed to police the event" (verb) Note that it is not usually regarded as a proper noun except when referring to a pop-group with that name or to a specific body, usually as a shortened form of an official title, or when the adjective is part of a title, as in 'Police Commissioner'.

Sir, I have two doubts in this sentence. Why we should add has instead of have Why not we add an before excellent in the sentence. please explain.

I have You have He/she/it has ... &c The sentence construes as: "I am ... [something]" where [something] is "a native Tamil speaker who has ..." I'm afraid that it is quite difficult to explain WHY 'who' should be in the third person. I think you just have to accept that it is in this instance. An article is not used because 'experience' is an attribute and not a particular event in time as in "I had an interesting experience yesterday". (Also, you should have asked: "Why do we not add 'an' before 'excellent' in the sentence." OR "Why don't we ..." ... though, obviously, I completely understood your meaning. )

Sir , shall we write like why should not we add an before excellent...... Is it correct form of asking ?

This is an alternative - to avoid the relative pronoun altogether and to construct two separate statements joined by a conjunction: "I am a native Tamil speaker." + "I have excellent experience in translation." = "I am a native Tamil speaker and [I] have excellent experience in translation." Another possibility would be: "I am a native Tamil speaker with excellent experience in translation."