Help me do v/s help me to do

Hi karansardana;

1. Please help me do that.
2. Please help me to do that.
3. Please help me in doing that.

Sentences 1 and 2 are interchangeable. I slightly prefer #1.
#3 is less common. It is grammatically correct. It seems more formal and elevated to me.

Thanks AlpheccaStars,

By the way,

I was thinking of one more form, which is I'd help you in doing of that.

I don't think 'doing of a thing' is ungrammatical, right ?

Regards,
Karan

"doing of a thing" is not grammatical, unless you are using "doing" to stand in for another verb.

The opening of the door startled us all.
The resulting weakening of the levees was a great concern.

how about 'his doing was deplorable'

Can't doing be synonymous with 'implementation' ?

Nothing deflates impossibility like the doing of it. Can I not use doing as a noun ? I think, I can, No ?

Yes, doing can be used as a noun. Here are some sentences:

He was rewarded for doing a good job.
Mother Theresa set an example of modern sainthood by doing good deeds and helping the poor.
Doing well in school helps you to be successful later in life.
That crime was his doing, not mine.
She was born to be an actress; she could not imagine hers