Question

I know his sister change the voice

Answer 1

Answer:

I know his sister : Change the voice

• The given sentence is said to change into Passive Voice and it is : His sister is known to me.

• The given sentence is an example of Simple Present Tense and the base form 'know' confirms it.

• 'His sister' was Object but it has turned Subject in Passive Voice and again it is also a Singular Number, that's why 'is' has been used and Main Verb's 3rd form is used and here it is 'know = 'known', according to grammatical rules after 'known' 'to' is always used, not 'by' is used.

• Therefore: 'His sister is known to me' is correct.

Answer 2

Answer:

His sister is known to me.

Explanation:

The active voice is in Simple Present Tense. When we convert the Simple Present Tense into Passive Voice we use 'is/am/are+v3 (Past Participle). We use the preposition 'to' with the verb 'know' in such structure. The other rules of the active-passive voice are followed as usual. Rules such as subject becomes object and vice-versa.