Prima di cena, impasto il pane con mia sorella.

It means before dinner.

• prima = before / earlier
• di = of / before
• cena = dinner

As a whole, prima di cena is a very common time expression in Italian.

In a simple time expression like this, Italian often uses prima di + meal without an article:

• prima di colazione = before breakfast
• prima di pranzo = before lunch
• prima di cena = before dinner

If you say prima della cena, it sounds more specific: before the dinner, meaning a particular dinner or event.

So in this sentence, prima di cena is the natural general expression.

Here impasto is the first-person singular present tense of the verb impastare.

So:

• impastare = to knead / to mix dough
• impasto = I knead / I mix

In this sentence, it means I knead/make the bread dough.

A learner may notice that impasto can also be a noun in other contexts, meaning dough, mixture, or paste, but here it is clearly the verb.

Italian often drops the subject pronoun when it is already clear from the verb ending.

• impasto already means I knead
• so io is not necessary

You could say io impasto if you want emphasis, for example:

• Io impasto, tu cucini. = I knead, you cook.

But in a normal sentence, impasto by itself is perfectly natural.

Italian uses the definite article much more often than English.

So even where English might say bread, Italian often says the bread:

• mangio il pane = I eat bread
• compro il pane = I buy bread
• impasto il pane = I make/knead the bread

Here il pane is the normal Italian way to say it.

Yes, literally it suggests kneading the bread, but in natural English it often means making the bread dough or preparing bread.

Italian can use pane where English might be more explicit and say bread dough. So the exact English wording depends on context, but the Italian is completely normal.

Yes. Con mia sorella means with my sister, in the sense of together with her.

So the sentence means that the speaker and the sister are doing the bread-making together.

With singular family members, Italian usually does not use the article before the possessive:

• mia sorella = my sister
• mio fratello = my brother
• mia madre = my mother

So con mia sorella is exactly what you would expect.

However, the article is used in some cases, for example with:

• plural family members: i miei fratelli
• modified family members: la mia sorella maggiore
• affectionate/diminutive forms in some contexts

But in this sentence, mia sorella is the standard form.

Yes, that is also correct.

Italian word order is fairly flexible. Both of these work:

• Prima di cena, impasto il pane con mia sorella.
• Impasto il pane con mia sorella prima di cena.

Starting with Prima di cena puts the time expression first, which gives it a little more emphasis.

The comma is used because Prima di cena is an introductory time phrase placed at the beginning of the sentence.

So:

• Prima di cena, impasto il pane con mia sorella.

This is similar to English:

• Before dinner, I knead the bread with my sister.

The comma helps readability. In some informal writing, people might omit it, but using it is very normal.

It can be either, depending on context.

The Italian present tense can express:

• something happening now
• a habitual action
• a general routine

So this sentence could mean:

• Before dinner, I’m kneading the bread with my sister.
• Before dinner, I knead the bread with my sister.

Without more context, both are possible.

The preposition con can sometimes mean with in different senses, but here the meaning is clearly together with because the object is a person:

• con mia sorella = with my sister

If it were a tool or ingredient, then con could mean using or with in that sense:

• impasto il pane con le mani = I knead the bread with my hands
• impasto il pane con acqua e farina = I make the bread with water and flour

So the noun after con helps you understand the meaning.

A simple breakdown is:

• Prima di cena = time expression
• impasto = verb, 1st person singular present
• il pane = direct object
• con mia sorella = prepositional phrase meaning with my sister

So the structure is basically:

Time phrase + verb + object + companion

That makes it a very useful model sentence for everyday Italian.