Pour le petit-déjeuner, je mange parfois des noix avec du miel, et ma sœur prend des amandes.

It gives the context first: for breakfast.

French often puts a time or situation phrase at the beginning of the sentence, just as English can say For breakfast, I sometimes eat... The comma simply separates that introductory phrase from the main clause.

Also, pour le petit-déjeuner suggests as a breakfast choice or for breakfast. A similar phrase, au petit-déjeuner, is also possible, but that feels more like at breakfast / during breakfast.

Because it is a fixed compound noun meaning breakfast.

Literally, the parts come from petit and déjeuner, but together they function as one word naming a meal. The hyphen helps show that it is a single unit. In standard everyday French, le petit-déjeuner is the usual form for the noun breakfast.

In French, short adverbs like parfois, souvent, toujours, and déjà are often placed after the conjugated verb in a simple tense.

So:

• Je mange parfois des noix = I sometimes eat nuts

That is the most neutral word order here.

Other positions are possible for emphasis, such as Parfois, je mange des noix, but je mange parfois is very natural and standard.

Because French uses different articles depending on whether the noun is:

• countable and plural → des
• uncountable / mass noun → du, de la, or de l’

Here:

• des noix = some walnuts / some nuts
• du miel = some honey
• des amandes = some almonds

More specifically:

• noix is a feminine noun: une noix, plural des noix
• amande is feminine: une amande, plural des amandes
• miel is masculine: du miel

So the article changes with both number and gender, and also with whether the thing is seen as a countable item or a substance.

Because French usually does not leave nouns bare the way English often does.

English can say:

• I eat nuts
• with honey

But French normally needs a determiner:

• Je mange des noix
• avec du miel

So je mange noix or avec miel would sound incomplete in ordinary French.

This is a very common difference between English and French: French usually wants an article where English often uses none.

Because prendre can be used in French to mean to have when talking about food, drinks, meals, or medicine.

So:

• ma sœur prend des amandes means something like my sister has/eats almonds

It does not have to mean she is physically taking them with her. In food contexts, prendre is very natural.

You could also say ma sœur mange des amandes, and that would be correct too. But prendre is common when talking about what someone has for a meal or snack.

Because in French, a possessive adjective like mon, ma, mes already does the job that the/my would do in English. You do not add a regular article in front of it.

So:

• ma sœur = my sister
• not la ma sœur

Also, ma agrees with sœur, not with the speaker. Since sœur is feminine singular, French uses ma.

Noix is pronounced roughly nwah.

A few useful points:

• the oi makes the wah sound
• the final x is silent
• singular and plural are written the same way: une noix / des noix
• singular and plural sound the same too

So the article tells you whether it is singular or plural:

• une noix = one walnut
• des noix = some walnuts

Sœur is pronounced approximately sur or sir, but neither English version is perfect. The French vowel has no exact English equivalent.

A more precise description is:

• s
• then a vowel a bit like the one in bird, but with rounded lips
• then the French r

The spelling œ represents a single vowel sound, not two separate vowels. So sœur is one smooth syllable, not something like so-eur.

If you know IPA, it is usually written /sœʁ/.