I'm so confused whether these clauses can be reduced or not

Question

We know that defining relative clauses can be reduced. Let's look at some examples.

1. The boy whom I called yesterday knows you.

= The boy I called yesterday knows you. (The relative pronoun is omitted as it's the object of the clause)

2. The boy who is sitting next to you lives in Kolkata.

= The boy sitting next to you lives in Kolkata. (The relative pronoun is the subject of the clause and it's followed by a be verb so we've omitted the relative pronoun and the be verb both)

3. The girl who lives in Kolkata is beautiful.

= The girl living in Kolkata is beautiful. ( There is no be verb after the relative pronoun so we change the main verb into its progressive form and then omit the relative pronoun)

4. My friend who is a teacher is a good hearted person.

= My teacher friend is a good hearted person.

Now my question is if they are non defining relative clauses , can we omit by ways mentioned above ? Can the following sentences containing non defining clauses reduced?

1. Ram,whom I called yesterday, is a very good boy.
2. Rima, who is sitting next to you, is very beautiful.
3. My mother, who lives in Delhi, is very hardworking.
4. My father, who is a doctor, loves me so much.

Answer 1

You can't reduce any of the four examples you give because in each instance you are speaking of a specific person. But suppose, instead, you had five brothers. Then a sentence such as "My brother living in Delhi..." would narrow the list of brothers to just (presumably) the one living there. You also could say, "My brother who lives in Delhi ..." because that, too, narrows the reference to the specific brother who lives there. You even could say, "My brother, who lives in Delhi, ...," but that sounds a little strange when you have multiple brothers, although it is technically acceptable.