For physical hardness:
* Ng'ang'a: This is the most common and straightforward translation for physical hardness, like a hard rock or a hard surface.
* Ng'ovu: This term is also used for physical hardness, but can also imply strength and resilience.
For difficult or challenging:
* Ng'omango: This is the most common translation for "hard" when describing something difficult, like a hard task or a hard time.
* Ng'umu: Similar to "ng'omango," this term indicates something challenging or requiring a lot of effort.
* Mulima: This term is often used to describe a difficult situation or a person who is difficult to deal with.
For strong or firm:
* Ng'ang'a: This can be used to describe a strong or firm object, such as a hard rope or a hard grip.
* Ng'ovu: This can also be used to describe strength and firmness.
The best translation will depend on the specific context of the English sentence.
It's important to note that the Luhya language is diverse, with various dialects. The specific words and their nuances may differ slightly depending on the region.