Сегодня миксер сломался, поэтому мне пришлось мешать тесто руками.

Сломался means broke / broke down in an intransitive sense: the mixer itself stopped working.

• миксер сломался = the mixer broke
• я сломал миксер = I broke the mixer

So the -ся form is often used when something happens to the subject itself, without stating an outside agent.

In this sentence, the idea is simply that the mixer stopped working, so сломался is the natural choice.

Because it agrees with миксер, which is a masculine noun.

In the past tense, Russian verbs change for gender in the singular:

• masculine: сломался
• feminine: сломалась
• neuter: сломалось

Since миксер is masculine, you get миксер сломался.

Because пришлось is used in an impersonal construction, and the person affected goes in the dative case.

So:

• мне пришлось = I had to
• literally something like: it fell to me / it became necessary for me

That is why Russian uses мне, not я.

More examples:

• Мне пришлось уйти. = I had to leave.
• Нам пришлось ждать. = We had to wait.

Here пришлось means had to or ended up having to.

It often suggests necessity caused by circumstances, not personal choice.

So in this sentence:

• мне пришлось мешать тесто руками = I had to mix the dough by hand

The idea is: because the mixer broke, there was no other option.

This is slightly different from я должен был..., which can sound more like obligation or duty.

Because пришлось is commonly used impersonally.

Russian often expresses necessity with an impersonal verb plus a dative experiencer:

• мне пришлось
• ему пришлось
• нам пришлось

There is no normal nominative subject like я or он controlling the verb. The construction itself expresses that something became necessary for someone.

Мешать here means to stir / mix. It is a very common verb for mixing ingredients.

• мешать суп = stir soup
• мешать тесто = mix dough

Смешивать often means to combine / mix together things, especially emphasizing bringing separate things into a mixture. It is possible in some contexts, but мешать is more natural here for the physical action of mixing dough.

Depending on context, Russian might also use замешивать / замесить тесто, which is more specifically to make/knead dough. But in this sentence, мешать тесто is perfectly understandable and natural.

After пришлось, Russian often uses the infinitive that describes the needed action in a general or process sense.

Мешать is imperfective, focusing on the activity itself:

• мне пришлось мешать тесто = I had to mix the dough

If you used a perfective verb, it would focus more on completion of a single whole action. In many real-life situations, Russian prefers the imperfective after пришлось when talking about what someone had to do.

So here мешать sounds natural because it emphasizes the task/process.

Тесто is the direct object of мешать, so it is in the accusative case.

But тесто is a neuter inanimate noun, and for many neuter inanimate nouns, the accusative singular is identical to the nominative singular.

So:

• nominative: тесто
• accusative: тесто

That is why the form does not change.

Руками is the instrumental plural of руки and means with (one’s) hands / by hand.

Russian often uses the instrumental case to show the instrument or means by which something is done.

So:

• мешать руками = mix with your hands / by hand

This is very natural Russian.

Because when people physically mix dough, they usually do it with their hands, and Russian naturally expresses that in the plural.

• рукой = with one hand
• руками = with hands

Even when English says by hand, Russian often uses the plural if two hands are realistically involved.

They are similar, but not exactly the same.

• руками = literally with the hands
• вручную = manually / by hand, more adverbial and slightly more abstract

In this sentence, руками feels vivid and physical, which fits mixing dough very well.

Compare:

• пришлось мешать тесто руками = had to mix the dough with my hands
• пришлось делать это вручную = had to do it manually

Both are possible, but руками is especially natural here.

Because the sentence has two parts:

1. Сегодня миксер сломался
2. поэтому мне пришлось мешать тесто руками

Поэтому means therefore / so / that’s why, and it connects the second part to the first as a consequence. In Russian, this is normally separated by a comma.

So the structure is:

• X happened, therefore Y happened.

Yes. Russian word order is flexible, so поэтому can move, though some positions are more natural than others.

For example:

• Сегодня миксер сломался, поэтому мне пришлось мешать тесто руками.
• Сегодня миксер сломался, мне поэтому пришлось мешать тесто руками.

The original version is the most neutral and natural for learners.

Putting поэтому at the start of the second clause is very common because it clearly marks the consequence.

Russian often puts time expressions near the beginning of the sentence to set the scene.

• Сегодня миксер сломался... = Today the mixer broke...

This sounds very natural. It tells the listener right away when the event happened.

Russian word order is flexible, so other orders are possible, such as:

• Миксер сегодня сломался...

But the original sentence is a very normal way to present the information.

Not naturally. A word-for-word translation would sound strange in English because the Russian grammar works differently.

A better natural translation is:

• Today the mixer broke, so I had to mix the dough by hand.

The important grammar differences are:

• мне пришлось = I had to
• руками = with my hands / by hand

So while the Russian structure is different, the natural English meaning is straightforward.

A natural stress pattern is:

• Сего́дня
• ми́ксер
• слома́лся
• поэ́тому
• мне́
• пришло́сь
• меша́ть
• те́сто
• рука́ми

This can help with pronunciation, especially for words like поэтому and пришлось, which learners often mis-stress.