Мало того что на проспекте была пробка, так ещё и троллейбус сломался.

It is a fixed Russian pattern used to pile one bad or surprising thing on top of another.

In this sentence:

• Мало того что на проспекте была пробка, так ещё и троллейбус сломался.

the pattern means something like:

• Not only was there a traffic jam on the avenue, but on top of that the trolleybus also broke down.
• As if the traffic jam wasn’t enough, the trolleybus broke down too.

A very literal translation of the individual words would sound strange in English, so it is best to learn the whole structure as one unit.

Pattern:

• Мало того что X, так ещё и Y.

Meaning:

• Not only X, but also Y
• As if X weren’t enough, Y too

It often carries annoyance, frustration, or emphasis.

Literally:

• мало = little / not much
• того = of that
• что = that

But in this expression, you should not translate it word for word. The phrase has become idiomatic.

You can think of мало того что as meaning:

• it wasn’t enough that...
• not only that...

So even though the literal pieces may seem odd, the full expression is very common and natural in Russian.

Так ещё и introduces the extra, aggravating fact.

In this sentence:

• Мало того что ... , так ещё и троллейбус сломался.

it means:

• but on top of that...
• and to make matters worse...
• what’s more...

The parts contribute slightly different shades:

• так helps link the second part strongly to the first
• ещё = still / yet / in addition
• и = also / even

Together, they create a strong additive meaning.

You will often see:

• Мало того что X, так ещё и Y
• Мало того что X, так ещё Y

The и is very common and adds to the feeling of too / also.

Because the sentence contains two clauses and a fixed correlative structure.

Break it up like this:

• Мало того что на проспекте была пробка, так ещё и троллейбус сломался.

The first clause is:

• на проспекте была пробка

The second clause is:

• троллейбус сломался

Russian separates them with a comma. The first comma appears before что because of the set expression мало того что introducing a clause, and the second comma marks the boundary before the next clause introduced by так ещё и.

So the punctuation reflects the larger structure:

• Мало того что [clause 1], так ещё и [clause 2].

На проспекте is normal Russian.

Russian commonly uses на with streets, avenues, squares, and similar places:

• на улице = on the street
• на проспекте = on the avenue
• на площади = in/on the square

So:

• на проспекте была пробка

means:

• there was a traffic jam on the avenue

Even though English often uses on or in differently depending on context, Russian simply uses the conventional preposition here: на + prepositional case.

Проспекте is the prepositional singular of проспект.

Not exactly.

Проспект usually means:

• a major avenue
• a broad important city street

It is not just any small street. Compare:

• улица = street
• проспект = avenue / boulevard-like major street

So на проспекте gives a slightly more specific urban image than just на улице.

Because пробка is a feminine noun.

In the past tense, Russian verbs agree with gender and number:

• masculine: был
• feminine: была
• neuter: было
• plural: были

Since пробка is feminine, you get:

• пробка была or была пробка

So:

• на проспекте была пробка = there was a traffic jam on the avenue

No. Пробка has several meanings.

Common ones include:

• cork (as in a bottle cork)
• traffic jam
• stopper / plug in some contexts

In this sentence, the meaning is clearly:

• traffic jam

This is very common Russian usage.

For example:

• Мы застряли в пробке. = We got stuck in traffic.

Russian often does not use a separate equivalent of English there is / there was in the same way.

Instead, Russian typically just states the location and the thing that existed:

• На проспекте была пробка.

Literally, this is closer to:

• On the avenue was a traffic jam.

Natural English turns that into:

• There was a traffic jam on the avenue.

So nothing is missing in Russian. This is just a normal difference between the two languages.

Сломался comes from сломаться, which means:

• to break down
• to get broken
• to stop working because something broke

For vehicles and machines, сломаться is very common:

• Машина сломалась. = The car broke down.
• Компьютер сломался. = The computer broke.

In your sentence:

• троллейбус сломался = the trolleybus broke down

This is the natural verb here.

The -ся ending marks the verb as reflexive, but reflexive verbs in Russian are not always literally “oneself.”

With сломать and сломаться, there is an important difference:

• сломать что-то = to break something
• сломаться = to break / break down

Compare:

• Он сломал телефон. = He broke the phone.
• Телефон сломался. = The phone broke / stopped working.

So in your sentence:

• троллейбус сломался

means the trolleybus itself broke down, not that someone actively broke it in the sentence.

Because троллейбус is masculine singular.

Russian past tense agrees with the subject:

• сломался = masculine singular
• сломалась = feminine singular
• сломалось = neuter singular
• сломались = plural

Since троллейбус is masculine, the correct form is:

• троллейбус сломался

Сломаться is perfective.

That means it presents the event as a completed whole: the breakdown happened.

In this sentence, that is exactly what you want:

• there was a traffic jam
• and then, on top of that, the trolleybus broke down

If you used the imperfective, it would sound different and would not fit as naturally here.

Aspect pair:

• ломаться = imperfective, to be breaking / to break repeatedly / to tend to break
• сломаться = perfective, to break down

So сломался highlights the actual completed incident.

Russian word order is flexible, and different orders can change emphasis.

Here:

• на проспекте была пробка
• троллейбус сломался

sound neutral and natural.

Some alternatives are possible:

• На проспекте пробка была...
• ...так ещё и сломался троллейбус.

But those would shift emphasis or sound more marked, depending on context.

A useful general point:

• Russian often puts new or important information later.
• It also uses word order for rhythm and emphasis more than English does.

In your sentence, the chosen order sounds smooth and standard.

There is usually a bit more emotional force than a plain English not only... but also...

The Russian pattern:

• Мало того что ..., так ещё и ...

often suggests irritation, complaint, or to make matters worse.

So depending on context, the best English translation might be:

• Not only was there a traffic jam on the avenue, but the trolleybus also broke down.
• As if the traffic jam on the avenue wasn’t enough, the trolleybus broke down too.
• There was a traffic jam on the avenue, and to make matters worse, the trolleybus broke down.

The second and third versions often capture the tone better.

It is mostly neutral conversational Russian.

Nothing in it is slang, but the structure Мало того что ..., так ещё и ... is especially common in spoken and everyday written language when someone is complaining or emphasizing a chain of problems.

So it is:

• natural
• common
• expressive
• not overly formal

You could absolutely hear it in everyday speech.

Yes. In actual writing, you will often see:

• Мало того, что на проспекте была пробка, так ещё и троллейбус сломался.

That comma after того is very common because что introduces the clause.

You may encounter slightly different punctuation practices depending on style, but the version with the comma after того is standard and especially common in edited writing.

So for learners, a very safe version to remember is:

• Мало того, что X, так ещё и Y.

Yes, that is possible.

Compare:

• так ещё и троллейбус сломался
• так ещё троллейбус сломался

Both can occur, but и strengthens the sense of also / too / on top of that. In your sentence, так ещё и sounds very natural.

So:

• without и: still correct
• with и: often a bit more emphatic and idiomatic

For learners, it is useful to remember the fuller pattern:

• Мало того что ..., так ещё и ...