Learn Hardcore Swahili: Bibi huvaa leso kichwani kila siku, hata akiwa nyumbani tu. - Grandmother wears a headscarf on her head every day, even when she is just at home.

Bibi huvaa leso... = Grandma habitually wears a headscarf…
Bibi anavaa leso... = Grandma is wearing / wears a headscarf (more neutral present, can sound more like “right now” or a general fact).

So huvaa focuses on the habit or routine, while anavaa is just present tense without that strong “every time / as a rule” feeling.

Why is there no a- subject prefix in huvaa? Where did the “she” go?

With the habitual marker hu-, Swahili normally drops the subject prefix on the verb.

Ordinary present: a-na-vaa → she wears / she is wearing
Habitual: hu-vaa → she (normally) wears

The subject is understood either from context or from an explicit noun like Bibi before the verb. So Bibi huvaa... already tells you who is doing the action; you do not say Bibi ahuvaa.

What is a leso exactly? Is it just any scarf?

A leso is a specific kind of light, usually square piece of cloth, common in East Africa. People often:

tie it on the head as a headscarf,
use it to cover shoulders or chest,
or use it for small daily tasks (wiping, carrying small things).

It is not as large as a khanga and is more like a versatile headscarf / kerchief rather than a thick winter scarf.

What does kichwani mean, and why is the ending -ni used?

Kichwani comes from kichwa (head) + the locative ending -ni.

kichwa = head
kichwani = on the head / at the head

The -ni suffix often adds a place meaning:

nyumba → nyumbani = at home
soko → sokoni = at the market

So leso kichwani literally means “a leso on (her) head.”

Could you also say leso kwenye kichwa instead of leso kichwani? Is there a difference?

You can say leso kwenye kichwa, and people will understand it as “a scarf on the head.”
However, leso kichwani is:

more natural and idiomatic in Swahili,
more compact, because -ni already expresses the “on/at” sense.

Kwena / kwa / juu ya + body part are possible, but for very common body-part locations, Swahili often prefers the -ni form: mkononi (on the arm), miguuni (on the legs/feet), kichwani (on the head).

What does hata do in hata akiwa nyumbani tu?

In this sentence, hata means even.
So hata akiwa nyumbani tu is “even when she is just at home.”

It emphasizes that she still keeps the scarf on, even in situations where you might expect her not to (because she is only at home, not going out).

How is akiwa formed, and what does it mean here?

Akiwa is made of:

a- = “he/she” (3rd person singular subject prefix)
-ki- = a marker often meaning when / while / if
-wa = the verb kuwa (“to be”) without the initial ku-

So akiwa ≈ “when/while she is.”

In context:

hata akiwa nyumbani tu = even when she is at home (only).

It introduces a time/condition clause: “(even) when/whenever she is at home.”

Could we say hata anapokuwa nyumbani instead of hata akiwa nyumbani? Is there a difference?

Yes, hata anapokuwa nyumbani is also grammatical and understandable.

akiwa nyumbani is shorter, very common in spoken and everyday written Swahili.
anapokuwa nyumbani can sound a bit more formal or explicit about the “when” idea.

Meaning-wise here, both are “even when she is at home”, with almost no change in practical meaning.

What does tu add to the meaning in nyumbani tu?

Tu means only / just / merely.
So nyumbani tu is “just at home / only at home.”

In the full sentence, it suggests:

she wears the leso even when she’s just at home,
i.e. not only when she goes out or expects visitors.

It gives a limiting / downplaying nuance: there is nothing special about the situation, yet the habit continues.

Is the word order fixed? Could I say Bibi huvaa leso kila siku kichwani instead?

Swahili word order is somewhat flexible, especially for time and place phrases. Your alternative

Bibi huvaa leso kila siku kichwani

is understandable. However, the more neutral, typical ordering is:

subject – verb – object – place – time
→ Bibi huvaa leso kichwani kila siku

Moving kila siku or kichwani can be done for emphasis or style, but beginners are usually safest keeping “place before time.”

Does Bibi always mean “grandmother”? Could it also mean “lady” or “Mrs.”?

Bibi can mean several related things, depending on context:

grandmother (very common everyday meaning),
an older woman (respectful, like “ma’am”),
in some contexts, a title similar to “Mrs.” or “Madam”.

In this sentence, without more context, “Grandma” or simply “an old lady” is a natural understanding. The capitalization here is just because it is the first word of the sentence.