Wastani wa alama za darasa letu umeongezeka mwezi huu.

A helpful literal breakdown is:

• Wastani = average
• wa = of
• alama = marks / scores / grades
• za = of
• darasa letu = our class
• umeongezeka = has increased / has gone up
• mwezi huu = this month

So the structure is roughly:

average of scores of our class has-increased this month

Natural English would be something like The average score for our class has increased this month or Our class’s average marks have gone up this month.

Because Swahili normally does not use articles like the or a/an.

So wastani can mean:

• an average
• the average
• simply average

The exact sense comes from context. In this sentence, English naturally uses the: The average score..., but Swahili does not need a separate word for it.

In Swahili, the word that links nouns in an of relationship changes to match the noun before it.

So:

• wastani wa alama = average of scores
• alama za darasa letu = scores of our class

These connectors agree with the noun class of the noun that comes before them.

So here:

• wa matches wastani
• za matches alama (used here with a plural meaning)

This kind of agreement is very normal in Swahili and is one reason the language can look more complicated than English at first.

It is a chain of related nouns:

• wastani = average
• wa alama = of scores
• za darasa letu = of our class

So the whole phrase means:

the average of our class’s scores

Swahili often builds noun phrases this way:

noun + connector + noun + connector + noun

instead of using an English-style apostrophe, as in our class’s average.

Because the possessive our has to agree with the noun class of darasa.

The basic possessive stem is -etu = our, but its form changes depending on the noun:

• darasa letu = our class
• kitabu chetu = our book
• mwalimu wetu = our teacher

So letu is simply the correct agreeing form for darasa.

Here it has a plural/collective meaning: scores, marks, or grades.

A useful thing to know is that alama often looks the same in singular and plural. Context and agreement help you tell the difference.

In this sentence, za darasa letu shows that alama is being treated as plural, so the meaning is something like the scores/marks of our class.

Because the verb agrees with the subject, and the subject here is wastani.

So:

• Wastani ... umeongezeka
• The average ... has increased

The important point is that the verb agrees with average, not with scores.

That is why the verb is singular in meaning: it is the average that has gone up.

Umeongezeka can be broken down like this:

• u- = subject agreement for wastani
• -me- = perfect aspect, often like has
• -ongezeka = increase / become greater / go up

So umeongezeka means:

• has increased
• has gone up

This is a very common Swahili tense/aspect pattern for something that has happened and is relevant now.

Because these two verbs are different:

• kuongezeka = to increase, to go up, to become greater
  
  • usually intransitive
• kuongeza = to increase something, to add something
  
  • usually transitive

In this sentence, the average itself is going up, so Swahili uses kuongezeka:

• Wastani umeongezeka = The average has increased

If you were talking about someone increasing something, you would use kuongeza:

• Mwalimu ameongeza alama = The teacher has increased the marks

Because in normal Swahili, the demonstrative usually comes after the noun:

• mwezi huu = this month
• wiki hii = this week
• mwaka huu = this year

So the order is usually:

noun + this/that

That is why mwezi huu is the standard form here.

Swahili often uses time expressions without a preposition.

So just as English says:

• this month
• today
• last year

Swahili says:

• mwezi huu = this month
• leo = today
• mwaka jana = last year

So umeongezeka mwezi huu naturally means has increased this month. No extra word like in is needed.

Darasa can mean different but related things depending on context, such as:

• a class of students
• a lesson
• sometimes a classroom

In this sentence, darasa letu most naturally means our class as a group of students, because the sentence is about the class’s scores.

So here it means something like:

the average score of our class or our class’s average score.