tricky questions

[john_nash]

I hope someone could give me a hand on this enigma.
Since the present participle clauses are the reduced form of relative clauses, for example:

My sister who is looking left and right is trying to cross the road.
My sister looking left and right is trying to cross the road.

That's why they cannot be substituded for non-continuning actions, for example:
My sister who saw the car accident is terrified.
My sister seeing the car accident is terrified. (not correct)

I wonder If I could use "to-infinitive clause" to replace the relative clause, just like:
My sister to see the car accident is terrified.

This question can be helpful to everyone, pls help me.
pls,,,...

 

[Raymott]

I hope someone could give me a hand on this enigma.
Since the present participle clauses are the reduced form of relative clauses, for example:

My sister, who is looking left and right, is trying to cross the road.
My sister, looking left and right, is trying to cross the road.

That's why they cannot be substituded for non-continuning actions, for example:
My sister, who saw the car accident, is terrified.
My sister, seeing the car accident, is terrified. (not correct)

Unless you are trying to define which sister you mean, you need to use commas. I think you mean these clauses to be non-defining.

I wonder If I could use "to-infinitive clause" to replace the relative clause, just like:
My sister to see the car accident is terrified.
No, this doesn't make sense.

This question can be helpful to everyone, pls help me.
pls,,,...

R.

 

[mayita1usa]

I wonder If I could use "to-infinitive clause" to replace the relative clause, just like:
My sister to see the car accident is terrified.

It works if you invert it, but it makes more sense in the past tense:
My sister was terrified to see the car accident.