* Ao: This generally refers to the sky or atmosphere, and can be used for "cloud" in a broader sense.
* Ao mākia: This means "cloudy sky" and is more specific to clouds.
* Mau'u ao: This translates to "cloud wisp" and refers to a specific type of cloud formation.
The best choice would depend on the specific context of your usage. For example, if you're describing a beautiful, fluffy cloud, you might use "ao mākia." However, if you're talking about clouds in a more general sense, "ao" might be more appropriate.