Ni ina son ruwa sosai.

Because they do different jobs.

• ni is the independent pronoun I / me
• ina already includes the subject idea I am / I do in this kind of sentence

So ni is often used for emphasis, contrast, or to set the topic:

• Ni ina son ruwa sosai. = As for me, I like water very much
• Ina son ruwa sosai. = I like water very much

The version without ni is also completely normal.

Here, ina is a grammatical marker that shows first person singular and an imperfective/present-like meaning.

In simple terms, it helps make the sentence mean something like:

• I like
• I want
• I love

depending on context.

It is not a separate word for am in exactly the same way as English. It is part of the Hausa sentence pattern.

This is a very common learner question.

The basic form is so, but before a following noun it often appears as son. So:

• son ruwa = liking/love/want of water

This is a normal Hausa pattern. So in this sentence, son ruwa works together as the idea of liking/wanting water.

A useful comparison:

• Ina son ruwa. = I like/want water
• Ina so in tafi. = I want to go

Before a noun, you often see son. Before another clause, you often see so.

It can mean all of those, depending on context.

• want
• like
• love

With ruwa sosai, many learners will understand it as a general strong liking: I like/love water very much.

But in another context, Ina son ruwa could also mean I want water.

So the exact English translation depends on the situation.

The order is roughly:

• Ni = I / as for me
• ina = subject + present/imperfective marker
• son = like/want/love
• ruwa = water
• sosai = very much

So the sentence is built like this:

Ni + ina + son + ruwa + sosai

A natural English translation changes the order a little, but the Hausa structure is very normal.

ruwa means water.

In this sentence it is the thing being liked, wanted, or loved. So it is the object of son.

Hausa often uses a plain noun like this without needing a word like the or some unless the context makes that clear.

Because Hausa does not use articles in the same obligatory way English does.

So ruwa by itself can mean:

• water
• the water
• some water

depending on context.

In this sentence, the meaning is understood from the situation, not from an article.

sosai means very much, a lot, or sometimes just very.

In this sentence it strengthens the idea of son ruwa:

• Ina son ruwa sosai. = I like water very much

Putting sosai at the end is very normal in Hausa. It often comes after the word or phrase it intensifies.

Yes. That is perfectly natural.

• Ina son ruwa sosai. = neutral statement
• Ni ina son ruwa sosai. = more emphasis, as in Me, I really like water

So if you are just making a simple statement, leaving out ni is often the more neutral choice.

It could be either, depending on context.

• In a general conversation, it can mean I really like water
• If you are thirsty, it can mean I want water

The word sosai makes the sentence sound especially strong, so many people will hear it as a general preference unless the situation clearly suggests a request.

A common way is:

Ba na son ruwa sosai ba.

Here:

• Ba na ... ba is the negative frame
• son ruwa sosai stays in the middle

So you can think of it as:

• Ina son ruwa sosai. = I like water very much
• Ba na son ruwa sosai ba. = I do not like water very much

A rough English-friendly pronunciation is:

nee EE-na son ROO-wa so-SAI

Very roughly:

• Ni ≈ nee
• ina ≈ EE-na
• son ≈ son or sawn
• ruwa ≈ ROO-wa
• sosai ≈ so-SAI

The real Hausa sounds are a bit more exact than English spelling can show, but this approximation is good enough for a beginner start.