Ninaelewa nadharia hii.

Ninaelewa can be split into:

• ni- = I
• -na- = present tense / ongoing time
• -elewa = understand

So ni-na-elewa literally means something like I am understanding / I understand.

In natural English, it is usually just I understand.

In Swahili, the subject is usually built into the verb.

So in Ninaelewa, the ni- already means I. Because of that, you do not need to add mimi unless you want emphasis.

• Ninaelewa nadharia hii. = I understand this theory.
• Mimi ninaelewa nadharia hii. = I understand this theory / I, specifically, understand this theory.

The second version sounds more emphatic.

The -na- is the common present-tense marker in Swahili.

In a sentence like Ninaelewa, it usually gives the idea of:

• present time
• general present
• ongoing state

So it can cover meanings like:

• I understand
• I am understanding
  though English usually prefers I understand

With stative verbs like understand, English normally uses the simple present, but Swahili still uses -na-.

In Swahili, demonstratives such as this usually come after the noun, not before it.

So:

• nadharia hii = this theory

not hii nadharia in normal basic usage.

This is a major difference from English word order. Swahili often puts the noun first, then words that describe or point to it.

Swahili nouns belong to noun classes, and words like demonstratives have to agree with the noun class.

Nadharia takes the demonstrative hii, so:

• nadharia hii = this theory

That is because nadharia patterns with the noun class that uses hii for this.

This agreement system is very important in Swahili. You cannot choose the demonstrative only by meaning; it must match the noun class.

Nadharia is generally treated like a class 9/10 noun.

That is why you get forms like:

• singular: nadharia hii = this theory
• plural: nadharia hizi = these theories

A lot of borrowed nouns in Swahili fall into classes where the singular and plural noun form may look the same, and the agreement words show the difference.

You would usually say:

• nadharia hizi = these theories

Notice that nadharia itself may stay the same, but the demonstrative changes:

• hii = this
• hizi = these

So the agreement word helps show whether the noun is singular or plural.

Yes. This is a very normal Swahili structure:

• Ninaelewa = verb
• nadharia = object
• hii = demonstrative modifying the object

So the pattern is basically:

Verb + object noun + demonstrative

That gives:

• Ninaelewa nadharia hii.

This is a standard and natural way to say it.

Yes, absolutely.

• Ninaelewa nadharia hii. = neutral, normal
• Mimi ninaelewa nadharia hii. = more emphatic

Adding mimi is not necessary, because ni- already means I. But you can add mimi if you want contrast or emphasis, for example:

• Mimi ninaelewa nadharia hii, lakini yeye haelewi.
  I understand this theory, but he/she does not.

You would say:

• Sielewi nadharia hii.

This breaks down as:

• si- = negative I
• -elew- = understand
• -i = negative final vowel

So the affirmative and negative compare like this:

• Ninaelewa nadharia hii. = I understand this theory.
• Sielewi nadharia hii. = I do not understand this theory.

In dictionary form, many Swahili verbs end in -a. That final -a is the usual ending of the verb stem in affirmative forms.

So:

• dictionary form: kuelewa = to understand
• in the sentence: ninaelewa = I understand

You can think of -elewa as the verb part being used after the subject and tense markers.

The dictionary form is:

• kuelewa = to understand

Swahili dictionaries usually list verbs with ku-, which is the infinitive marker meaning to.

So:

• ku-elewa = to understand
• ni-na-elewa = I understand

A learner-friendly pronunciation guide would be:

• na-dha-ri-a

A few helpful points:

• Swahili vowels are usually pronounced clearly: a, e, i, o, u
• dh is pronounced like the th in this for many speakers
• each vowel is usually heard, so ri-a is not collapsed the way it might be in English

So nadharia is said with four clear syllable-like parts: na-dha-ri-a.

No. Swahili does not use articles in the same way English does.

So nadharia by itself can mean things like:

• a theory
• the theory
• theory

The exact meaning depends on context.

When you add hii, it becomes specific:

• nadharia hii = this theory

So Swahili often expresses definiteness through context or through words like demonstratives, rather than with separate articles like a and the.

Grammatically, the Swahili present form can cover that kind of meaning, but in normal English, I understand this theory is the best translation.

Because understand is a stative verb in English, English usually avoids I am understanding except in unusual contexts.

So for normal learning purposes:

• Ninaelewa nadharia hii. = I understand this theory.

That is the most natural English equivalent.