The next noun class is M-Mi class. Nouns in this class always begin with with "m", and pluralized by changing the "m" to a "mi". In Lesson 3, we learned that M-Wa class is principly made up of nouns describing human beings. With the M-Mi class (an all subsequent noun classes) the grouping criteria is more abstract. The M-Mi class is sometimes called the "tree class" as many objects within the class some sort of tree-like property, including trees themselves.

The tree class includes things that physically long like rivers, borders, and canals, or have some abstract length, like time, months, and years. Thing that have "branches" such as the human body, arms/legs, and plants are can also be found in this class. There are many expections to these classifications, and many nouns like bread, luggage, and restaurant have no obvious relationship to trees. In general, if one encounters a noun beinging with "m" that is not a person, it very likely belongs to the M-Mi class. The Lesson 4 M-Mi class nouns are:

The corresponding subject markers for M-Mi class nouns are:

In this lesson we also introduce the concept of passive voice. In both English and Swahili, it much more common to use the active voice, e.g., "I am selling fruit" than the passive voice, e.g., "The fruit is being sold by me". However, it is relatively simple to use the passive voice in Swahili, so it is deserves mention at this stage. In the simpliest case the passive voice is formed using the rule:

If the last two letters of a verb root are "consonant + a", the passive voice is formed by replacing "a" with "wa".

Examples of this rule can be seen in the first 4 Lesson 4 verbs: The Lesson 4 exercise includes only the Lesson 4 nouns and verbs. Good luck!