Guru kami senang melihat kemajuan kami di kelas bahasa Indonesia.

Indonesian often leaves out the verb to be in simple statements.

So:

• Guru kami senang = Our teacher is happy
• literally, it looks more like Our teacher happy

This is completely normal in Indonesian. You do not need adalah here. In fact, adalah would usually sound unnatural in this sentence.

In Indonesian, possessive words usually come after the noun.

So:

• guru kami = our teacher
• kelas saya = my class
• buku mereka = their book

This is the opposite of English, where possessives usually come before the noun.

This is an important Indonesian distinction:

• kami = we/us, but not including the listener
• kita = we/us, including the listener

In Guru kami senang melihat kemajuan kami..., the speaker is talking about our teacher and our progress, but the listener is probably not part of that group. So kami is the natural choice.

If the listener were one of the students too, kita might be possible in another context.

Because it serves two different roles:

• guru kami = our teacher
• kemajuan kami = our progress

Indonesian often repeats possessives where English might also repeat them. There is nothing wrong or unnatural about that here.

Senang means happy, glad, or pleased.

Melihat literally means to see, but in sentences like this it often means something like:

• to see
• to observe
• to witness
• to notice

So senang melihat kemajuan kami means:

• happy to see our progress
• pleased to see our progress

This is a very natural Indonesian expression.

Because the basic meaning needed here is simply to see.

• lihat = root
• melihat = active verb, to see

Other forms would mean different things:

• melihatkan can mean to show in some contexts
• melihat-lihat means to look around / browse / take a look casually

So melihat is the correct straightforward verb here.

Kemajuan means progress.

It comes from the root maju, which means advanced, forward, or to progress.

The pattern ke-...-an often turns a root into a noun. So:

• maju = to advance / forward
• kemajuan = progress / advancement

This is a very useful pattern to notice in Indonesian vocabulary.

Indonesian nouns usually do not have to change form for singular or plural.

So:

• guru can mean teacher or teachers
• kelas can mean class or classes

The context tells you which one is meant. Here, guru kami clearly means our teacher because the sentence is talking about one teacher.

If needed, Indonesian can show plural with reduplication, for example:

• guru-guru = teachers

But it is not necessary here.

It means in Indonesian class or in the Indonesian language class.

Breakdown:

• di = in / at
• kelas = class
• bahasa Indonesia = Indonesian language

So the whole phrase means the progress is happening in the Indonesian class.

A natural English translation is:

• Our teacher is happy to see our progress in Indonesian class.

Because di here is a preposition, not a verb prefix.

• di kelas = in class / in the class
  Here di is a separate word.

But in verbs:

• dilihat = seen / is seen
  Here di- is a prefix and is attached to the verb.

A very common learner issue is mixing these up. A good rule:

• di + place → usually written separately
• di- + verb → written together

Yes. Bahasa Indonesia is the standard name for the Indonesian language.

• bahasa = language
• Bahasa Indonesia = Indonesian

In careful writing, Indonesia is capitalized because it is a proper name.

Learners should know that in English, people sometimes casually say Bahasa, but in Indonesian the full phrase is bahasa Indonesia.

Yes, structurally it can be understood with the whole idea, but in normal interpretation it most naturally describes where the progress is happening:

• our progress in Indonesian class

It could also loosely feel connected to the situation of seeing, but the intended meaning is clearly that the students are making progress in that class.

If someone wanted to make the location of the teacher’s seeing more explicit, they might rephrase the sentence.

Indonesian verbs do not conjugate the way English verbs do.

So melihat stays melihat whether the meaning is:

• see
• saw
• will see
• are seeing

Time is usually understood from context or from time words such as:

• sekarang = now
• kemarin = yesterday
• besok = tomorrow
• sudah = already
• akan = will

In this sentence, the meaning is a general present situation, so no extra tense marker is needed.

Yes, you could, but it changes the structure slightly.

• senang melihat kemajuan kami = happy to see our progress
• senang dengan kemajuan kami = happy/pleased with our progress

Both are natural, but they are not exactly the same:

• melihat focuses on the teacher observing the progress
• dengan focuses more on the teacher’s positive feeling about the progress itself

The original sentence sounds very natural and expressive.

It is fairly neutral and completely natural.

It would work in:

• everyday speech
• classroom discussion
• writing by a learner
• a simple school-related text

Nothing in it is slangy or overly formal. It is a good model sentence for standard Indonesian.