Learn Hardcore Swahili: Moyo wangu unafurahi ninaposikia wewe unafaulu. - My heart is happy when I hear that you are succeeding.

moyo – heart
wangu – my
→ moyo wangu = my heart
u-na-furahi
- u- – subject marker for class 3 nouns like moyo (it)
- -na- – present tense marker (is / does / is currently)
- furahi – be happy, rejoice
  → unafurahi = (it) is happy / rejoices
ni-na-po-sikia
- ni- – I
- -na- – present tense marker
- -po- – when/where marker (situative)
- sikia – hear
  → ninaposikia = when I hear
wewe – you (singular, emphasized)
u-na-faulu
- u- – you (singular)
- -na- – present tense marker
- faulu – succeed
  → unafaulu = you are succeeding / you succeed

So very literally: My heart it-is-happy when-I-hear you you-are-succeeding.

Why does the sentence say moyo wangu (my heart) instead of just mimi (I)? Is this just a more poetic way to say “I am happy”?

Yes, moyo wangu is more expressive and emotional than simply saying mimi or ninafurahi.

Ninafurahi = I am happy.
→ Plain, neutral statement about your feelings.
Moyo wangu unafurahi = My heart is happy / My heart rejoices.
→ Feels more heartfelt, emotional, sometimes a bit poetic or emphatic.

People do use moyo wangu in everyday speech, especially when talking about deep feelings, gratitude, love, pride, or strong joy. It highlights the emotional depth, not just the fact that you are happy.

You could also say:

Ninafurahi ninaposikia unafaulu. – I am happy when I hear you are succeeding.

This is perfectly correct, just less “emotional” in wording.

Why is it moyo wangu unafurahi, and not nafurahi? What does u- in unafurahi refer to?

In moyo wangu unafurahi, the subject of the verb is moyo (heart), not mimi (I).

Swahili verbs agree with the grammatical subject using a subject marker:

ni- = I
u- = you (sing.), or it for certain noun classes
a- = he/she
u- also = “it” for class 3 nouns like moyo

So:

Ninafurahi. – I (ni-) am happy.
Moyo wangu unafurahi. – My heart (class 3) is happy → u- agrees with moyo.

Here, u- in unafurahi is not “you”; it is “it” referring to moyo.
Very literally: My heart, it-is-happy.

Why is it moyo wangu and not moyo langu or moyo yangu? How does wangu work here?

Swahili possessive forms (my, your, his, etc.) change according to the noun class of the thing possessed.

moyo belongs to the m-/mi- noun class (class 3 in many grammars).
For this class, the singular possessive my is wangu.

So:

moyo wangu – my heart
plural: mioyo yangu – my hearts (here the class 4 plural takes yangu)

Compare with other noun classes:

nyumba yangu – my house (class 9)
jambo langu – my matter / issue (class 5)
kitu changu – my thing (class 7)

So moyo wangu is the regular, correct combination for “my heart.”

What exactly does ninaposikia mean, and how is it formed?

Ninaposikia is a single verb form built from several pieces:

ni- – I
-na- – present tense marker
-po- – situative/relative marker meaning “when/where”
sikia – hear

So ni-na-po-sikia = ninaposikia → when I hear.

Functionally, ninaposikia introduces a time clause: when I hear (at the time that I hear).
In the sentence, it links your happiness to a specific situation:

Moyo wangu unafurahi ninaposikia…
→ My heart is happy when I hear…

What is the difference between ninaposikia and nikisikia? Could I say Moyo wangu unafurahi nikisikia wewe unafaulu?

Both forms can translate as when I hear, but they have slightly different flavors:

ninaposikia
- ni-na-po-sikia
- Often feels more like “at the time that I hear,” can refer to specific or repeated times.
- Very natural here.
nikisikia
- ni-ki-sikia
- -ki- often marks a general condition or repeated/whenever type situation.
- Often translates as “if/whenever I hear.”

So:

Moyo wangu unafurahi ninaposikia wewe unafaulu.
→ My heart is happy when I hear you are succeeding. (quite neutral, can be specific or habitual)
Moyo wangu unafurahi nikisikia wewe unafaulu.
→ My heart is (always) happy whenever I hear you are succeeding. (a bit more “every time / whenever”)

Your suggested sentence with nikisikia is grammatically correct and understandable.
Here ninaposikia is slightly more neutral and common, but both are used.

Why does the sentence say wewe unafaulu when unafaulu already means “you are succeeding”? Is wewe necessary?

No, wewe is not grammatically necessary; unafaulu already contains the subject “you” in the prefix u-.

unafaulu = you (sg) are succeeding.
wewe unafaulu = you are succeeding, you (emphasized) are the one succeeding.

Swahili subject pronouns (mimi, wewe, yeye, sisi, ninyi, wao) are usually:

omitted in neutral sentences, because the verb prefix already shows the subject.
included for emphasis, contrast, or clarity.

So wewe here adds emphasis:

My heart is happy when I hear that you (not someone else) are succeeding.

You could also say:

Moyo wangu unafurahi ninaposikia unafaulu.
→ Correct, but a bit less focused on “you specifically.”

Can I omit wewe and just say ninaposikia unafaulu? How does that change the meaning?

Yes, you can omit wewe:

Moyo wangu unafurahi ninaposikia unafaulu.

This is fully correct and natural. The difference is subtle:

… ninaposikia wewe unafaulu.
→ Slight emphasis on you. Maybe contrasting you with others, or emotionally highlighting you.
… ninaposikia unafaulu.
→ More neutral; it is simply talking about you, but without extra emphasis.

In many everyday contexts, speakers would be perfectly happy to drop wewe here.

Why isn’t there a word like kwamba (“that”) before wewe unafaulu? Could we say ninaposikia kwamba wewe unafaulu?

You can include kwamba, and it is correct:

Moyo wangu unafurahi ninaposikia kwamba wewe unafaulu.
→ My heart is happy when I hear that you are succeeding.

In Swahili, kwamba (“that”) is:

optional in many informal or spoken contexts;
more common in formal writing or when you need extra clarity.

So both are fine:

… ninaposikia wewe unafaulu.
… ninaposikia kwamba wewe unafaulu.

The version without kwamba is slightly lighter and very natural in speech.

What tense or aspect is unafaulu? How is it different from umefaulu?

unafaulu is in the simple present with -na-:

u-na-faulu
- u- – you (sg)
- -na- – present tense marker
- faulu – succeed
  → you succeed / you are succeeding.

umefaulu uses the perfect aspect:

u-me-faulu
- -me- – perfect marker
  → you have succeeded / you succeeded (with a present result).

So in this sentence:

… ninaposikia wewe unafaulu.
→ when I hear that you are succeeding / you succeed (maybe ongoing progress, or success in general).

If you say:

… ninaposikia umefaulu.
→ when I hear that you have succeeded (you already passed/achieved it).

Both are possible, but they describe slightly different kinds of success (ongoing vs completed).

Why is the order Moyo wangu unafurahi ninaposikia… and not Moyo wangu ninaposikia unafurahi…? Can I move ninaposikia?

Swahili prefers a clear main clause followed by the time/condition clause:

[Main clause] Moyo wangu unafurahi
[When-clause] ninaposikia wewe unafaulu.

So Moyo wangu unafurahi ninaposikia wewe unafaulu is the natural order:

My heart is happy when I hear you are succeeding.

Placing ninaposikia in the middle, like:

Moyo wangu ninaposikia unafurahi wewe unafaulu

would sound awkward or confusing to a native speaker.

You can, however, move the when-clause to the front:

Ninaposikia wewe unafaulu, moyo wangu unafurahi.
→ When I hear you are succeeding, my heart is happy.

Main point: keep each clause internally ordered as Subject–Verb–(object/etc.), and don’t split moyo wangu from unafurahi.

Is Moyo wangu unafurahi idiomatic in everyday Swahili, or does it sound very poetic?

It is both understandable and natural, but it does sound a bit expressive or emotional.

In casual conversation, people often just say:
- Ninafurahi kusikia unafaulu. – I’m happy to hear you’re succeeding.
- Nafurahi sana unafaulu. – I’m very happy you’re succeeding.
Moyo wangu unafurahi adds a stronger emotional tone, like:
- My heart is full of joy / My heart rejoices.

So it is not strange or old-fashioned, but it does carry a slightly more heartfelt, sometimes poetic flavor, suitable for warm, emotional, or formal messages.