1) This window is broken
2) This window is broken by children
Correct me if I am wrong. Verb IS in the first sentence has been used as Linking verb because IS is defining the subject window.
& in sentence sentence it is Helping verb because IS is supporting main verb broken to identify that action happened in present tense.
Linking verbs: Verbs that do not point to an action but join the subject and the subject subject complement in a sentence are known as linking verbs. They are the main verb in the sentence. They can be both transitive and intransitive verb. Ex: Be , look, appear, grow, seem, sound, taste, turn are used as linking verbs.
Sentence: I am a teacher.
I : subject / am - linking verb / a teacher : the subject complement .[ So, am connects the subject of the sentence to the subject complement ]
The window is broken .[ The window: subject / is : linking verb / broken : subject complement ]
So , is connects the subjects of the sentence of the sentence to the subject complement .
Auxiliary verbs: Verb that help others verbs indicate the tense or are used to carry the negation in sentence are called auxiliary verbs.
Examples: Be, do have. Be can be used as a verb of being as well as auxiliary verb. 1: Lionel messi is a footballer .[ is as a verb of being --- Lionel Messi > footballer] 2:Lionel Messi is playing football. [ is as the auxiliary verb - helping the main verb play in forming the present continuous tense to show the continuity of the action ]
To To + noun : to the hotel [ here to is a preposition ]
To + verb 1st form = to go [ here to is infinitive to ]
To +be + verb third form = to be done [ here to is infinitive in passive voice]
"is" could be either a copula or an auxiliary. If we're describing the window's current state, "is" is a copula:
The front door is red. That window is stiff. This window is broken by children. The gate is squeaky.
If we're in the middle of a narrative, "is" is an auxiliary:
A mob approaches the building. Men nail a notice on the door. One window has newspapers over it. This window is broken by children. Their parents don't notice.
This is the same whether you say "by children" or not.
A mob approaches the building. Men nail a notice on the door. One window has newspapers over it. This window is broken.
This last example is ambiguous. It could mean the window is broken by the mob, or that the window was already broken, so depending on the meaning, "is" could be either a copula or an auxiliary.
In the narrative, "is" indicates passive voice, where the agent (the one initiating the action) is not mentioned, or is mentioned using "by X". The passive sentence "This window is broken by children." means the same as the active sentence "Children break this window."
