Sizwe builds a wall encroaching on his neighbour Zakhele's land. Sizwe was unaware of the encroachment. Classify Sizwe's legal position.

The question describes a situation where Sizwe built a wall that encroaches on his neighbour Zakhele's land.

Let's break down Sizwe's legal position:

1. Control: Sizwe has physical control over the portion of Zakhele's land where the wall stands.
2. Intention: Sizwe built the wall on what he believed to be his own property. This indicates an animus domini (intention of an owner) regarding that specific piece of land.
3. Good Faith: The scenario states, "Sizwe was not aware that the new wall is encroaching on Zakhele, his neighbour's land." This means Sizwe acted in bona fide (good faith).
4. Lawfulness: Sizwe does not own the land on which the wall is encroaching. Therefore, his control over that part of Zakhele's land is unlawful.

Combining these points:

• Since Sizwe has physical control and the intention of an owner (he built a permanent structure, believing it to be on his land), he is a possessor.
• Since he was unaware of the encroachment, he is a bona fide possessor.
• Since he does not actually own the land, his possession is unlawful.

Therefore, Sizwe is a bona fide unlawful possessor.

Now let's evaluate the given options:

• a. mala fide unlawful holder: Incorrect, as Sizwe was bona fide (not aware) and acts as a possessor, not merely a holder.
• b. bona fide possessor: This accurately describes Sizwe. A bona fide possessor is someone who believes they are the owner and acts as such, but is not the true owner. This implicitly means they are an unlawful possessor.
• c. mala fide possessor: Incorrect, as Sizwe was bona fide (not aware).
• d. bona fide unlawful holder: Incorrect. A holder acknowledges another's ownership, whereas Sizwe, by building a wall, was asserting his own (mistaken) right to the land, indicating an intention to own, not merely hold.

The most accurate description for Sizwe is a bona fide possessor.

The final answer is $\boxed{\text{b}}$