Learn Hardcore Swahili: Mama hutandika shuka kitandani kabla ya kulala. - Mother spreads the bedsheet on the bed before sleeping.

This is a very common point for learners because English often uses simple present for habitual actions, while Swahili uses a special marker like hu-.

Why is there no subject prefix before hutandika? Shouldn’t it be something like anatandika?

With the habitual hu-, Swahili often does not use the normal subject marker.

So:

Mama anatandika = Mother is spreading
Mama hutandika = Mother usually spreads

In hutandika, the hu- itself signals the habitual sense, and the subject is understood from Mama.

This is different from many other tenses in Swahili, where a subject marker is required, such as:

a-na-tandika = she is spreading
a-li-tandika = she spread
a-ta-tandika = she will spread