Je mange un biscuit avec mon café du matin.

Usually, no. In normal French, you almost always need the subject pronoun before a conjugated verb: je mange, tu manges, il mange, etc.

Unlike English imperatives such as Eat!, plain mange by itself would normally be understood as a command, not I eat / I am eating.

So je is necessary here.

Mange is the present-tense form of the verb manger for je:

• je mange = I eat / I am eating
• tu manges = you eat
• il/elle mange = he/she eats

A useful thing to notice: je mange, tu manges, and il mange are all pronounced the same, even though they are spelled differently.

It can mean either one.

The French present tense often covers both:

• I eat
• I am eating

So Je mange un biscuit avec mon café du matin could mean:

• a general habit: I eat a biscuit with my morning coffee
• something happening now: I’m eating a biscuit with my morning coffee

Context tells you which meaning is intended.

Because French normally needs an article before a singular countable noun.

So:

• un biscuit = a biscuit
• le biscuit = the biscuit

English sometimes drops articles in places where French does not, but here both languages use one: a biscuit / un biscuit.

Not always.

In French, un biscuit usually means something like:

• a biscuit in British English
• a cookie or sometimes a cracker in American English, depending on context

It does not usually mean the soft American baked bread item called a biscuit.

So learners should be careful: this is a common vocabulary trap.

Because café is a masculine noun in French.

French possessive adjectives agree with the thing possessed, not with the owner:

• mon café = my coffee
• ma tasse = my cup
• mes biscuits = my biscuits

So even if the speaker is female, it is still mon café, because café is masculine.

Here, du is the contraction of de + le:

• de le → du

So:

• le café du matin literally = the coffee of the morning
• more naturally in English = the morning coffee

Important: this du is not the partitive some here. It is part of the expression du matin.

Because French often links nouns with de / du / de la / des where English uses one noun directly in front of another.

English:

• morning coffee
• evening paper

French:

• café du matin
• journal du soir

So du matin is a very normal French way to express morning as a description of the coffee.

They mean different things.

• du matin = of the morning / morning...
  • mon café du matin = my morning coffee
• ce matin = this morning
  • J’ai mangé un biscuit ce matin = I ate a biscuit this morning

So in your sentence, mon café du matin is naming a type or routine: the coffee you have in the morning.

Not necessarily. Here avec usually means together with or alongside.

So the idea is:

• I eat a biscuit with my morning coffee
• the biscuit accompanies the coffee

If you specifically wanted to say you dip it into the coffee, French would use a different expression, such as:

• Je trempe un biscuit dans mon café.
  = I dip a biscuit in my coffee.

Because that is the most natural word order here.

French commonly goes:

• subject + verb + direct object + extra phrase

So:

• Je
  • mange
    • un biscuit
      • avec mon café du matin

You can move parts around in French, but this version is the most straightforward and neutral.

It is possible, but it sounds less neutral and less natural in everyday speech.

French usually prefers:

• Je mange un biscuit avec mon café du matin.

Putting un biscuit later gives it extra emphasis or a more marked structure. For a learner, the original order is the safest choice.

Un is pronounced with a nasal vowel, roughly /œ̃/.

A few helpful points:

• the n is not pronounced as a normal n
• the vowel is nasal, so air comes through the nose
• English does not have an exact equivalent

So un biscuit is not pronounced like uhn bis-kweet. A closer guide is something like:

• un ≈ nasal vowel, no full n sound
• biscuit = bees-kwee

A careful pronunciation is approximately:

Je mange un biscuit avec mon café du matin
/ʒə mɑ̃ʒ œ̃ bis.kɥi a.vɛk mɔ̃ ka.fe dy ma.tɛ̃/

A few notes:

• je often sounds like zhuh or a very light zh
• mange rhymes roughly with the vowel in French sans, not with English mange as spelled
• un is nasal
• biscuit ends with -kwee
• café has a clear final é sound: ka-fay
• matin ends with a nasal vowel; the final n is not pronounced as a full consonant

Yes, and that can sound very natural.

Difference:

• Je mange un biscuit... = I eat a biscuit...
• Je prends un biscuit... = I have / take a biscuit...

With food and drink, prendre is often used where English says have:

• Je prends un café = I’m having a coffee
• Je prends un biscuit avec mon café = I’m having a biscuit with my coffee

So both are possible; mange is more specifically about eating.