Ni ina hutawa kawai.

I am just resting.

Breakdown of Ni ina hutawa kawai.

• ni: I
• ne: to be
• hutawa: to rest
• kawai: only

Questions & Answers about Ni ina hutawa kawai.

Do Ni and ina both mean I? Why are there two I’s in this sentence?

They are two different kinds of pronouns:

• Ni is the independent (emphatic) pronoun: I / me (as for me).
• ina is the continuous subject form: it already means I am (doing …) in one word.

So Ni ina hutawa kawai is literally like saying in English:

• Me, I’m just resting.
• As for me, I’m just resting.

You do not need both to make a grammatical sentence; Ni is there for emphasis or contrast, not to supply the basic subject.

Can I drop Ni and just say Ina hutawa kawai? Does it change the meaning?

Yes, and that’s actually the more neutral version.

• Ina hutawa kawai. → I’m just resting. (plain statement)
• Ni ina hutawa kawai. → Me, I’m just resting. (emphasises I / me; often contrastive)

Typical uses of the version with Ni:

• Answering “What about you?”
  Ni ina hutawa kawai. → Me, I’m just resting.
• Contrasting with others:
  Suna aiki, amma ni ina hutawa kawai.
  They’re working, but I’m just resting.

So yes, you can drop Ni; you simply lose the extra emphasis.