في الصباح أشرب الحليب في كوب كبير، ولا أضع فيه سكر.

Yes, both are possible.

• في الصباح literally means in the morning
• صباحًا also means in the morning / in the morning time

In this sentence, في الصباح is a very natural way to set the time frame first: In the morning, I drink...

So these are both fine:

• في الصباح أشرب الحليب
• أشرب الحليب صباحًا

The version with في الصباح feels a little more like setting the scene first.

In Arabic, expressions for parts of the day often use the definite article:

• في الصباح = in the morning
• في المساء = in the evening
• في الليل = at night / in the night

So the الـ here is completely normal. Arabic and English do not always use articles in the same way.

Because ص is a sun letter.

When الـ comes before a sun letter, the l sound assimilates to the next consonant. So:

• written: الصباح
• pronounced: aṣ-ṣabāḥ

You still write ال, but you do not pronounce the l separately.

Because the verb already shows the subject.

• أشرب = I drink
• أضع = I put

The prefix أَ- marks first person singular in the imperfect verb. So أنا is not necessary.

You can say أنا أشرب or أنا أضع, but that usually adds emphasis, like I drink, I put.

These are in the imperfect form, which can cover several meanings depending on context:

• I drink
• I am drinking
• I usually drink

Here, because of في الصباح (in the morning), the most natural meaning is habitual:

• In the morning, I drink milk...
• ...and I don’t put sugar in it.

So this sounds like a regular habit, not just something happening right now.

Because Arabic often uses the definite article with generic nouns, especially foods, drinks, and substances.

So:

• أشرب الحليب = I drink milk
• أحب القهوة = I like coffee

In English, we often leave these nouns bare: milk, coffee. In Arabic, using الـ is often the natural choice when talking about something generally.

Using حليب without الـ is possible in some contexts, but here الحليب sounds more natural for a general statement.

Yes, literally it is something like I drink the milk in a big cup.

Arabic often uses في to show that something is in a container:

• في كوب = in a cup
• في زجاجة = in a bottle

In English, we often prefer from a cup, because we focus on the source or instrument of drinking. Arabic can also use من in some contexts, but في كوب كبير is very natural when describing the milk as being in that cup.

Because adjectives normally come after the noun in Arabic.

So:

• كوب كبير = a big cup
• بيت جميل = a beautiful house
• سيارة جديدة = a new car

Arabic adjectives also agree with the noun in:

• gender
• number
• definiteness
• case

Here كوب is:

• masculine
• singular
• indefinite

So كبير is also:

• masculine
• singular
• indefinite

Because the meaning is a big cup, not the big cup.

Compare:

• كوب كبير = a big cup
• الكوب الكبير = the big cup

Since the noun is indefinite, the adjective must also be indefinite. Arabic matches them.

ولا is simply:

• و = and
• لا = not

So ولا أضع means:

• and I do not put
• or more naturally, and I don’t put

This is very common in Arabic: short particles like و are attached directly to the following word.

In Modern Standard Arabic, لا is the normal negation for a simple present or habitual imperfect verb.

So:

• أضع = I put
• لا أضع = I do not put / I don’t put

Using ما here would not be the standard neutral MSA choice for this kind of sentence.

فيه is made of:

• في = in
• ـه = it / him

So فيه means in it.

This is a very common Arabic pattern: a preposition plus an attached pronoun.

Examples:

• فيه = in it
• عليه = on it / on him
• عنده = at his place / he has

Grammatically, it could refer to either one, because both are:

• masculine
• singular

That means فيه could point back to:

• الحليب = the milk
• كوب = cup

In practice, the meaning is clear: the speaker means that no sugar is added to the drink. Whether you think of that as in the milk or in the cup, the idea is basically the same here.

If you wanted to remove the ambiguity, you could say:

• ولا أضع سكرًا في الحليب = and I don’t put sugar in the milk
• ولا أضع سكرًا في الكوب = and I don’t put sugar in the cup

Because the meaning is sugar as an unspecified substance, not the sugar.

In Arabic, an indefinite noun after a verb often has the sense of:

• some sugar
• any sugar

So:

• لا أضع فيه سكرًا = I don’t put sugar in it

If you said السكر, that would usually sound more like the sugar, referring to some specific sugar already known in the conversation.

Because normal Arabic writing usually leaves out short vowels and tanwīn.

So the fully vocalized version would be something like:

في الصَّباحِ أشرَبُ الحليبَ في كوبٍ كبيرٍ، ولا أضعُ فيه سكرًا.

But in ordinary writing, those endings are usually not written.

Under full grammar:

• الصباحِ is after في, so it is genitive
• الحليبَ is the object of أشرب, so it is accusative
• كوبٍ كبيرٍ is after في, so both are genitive
• سكرًا is the object of أضع, so it is accusative

Because Arabic often uses a simple everyday verb where English prefers a more specific one.

So:

• أضع فيه سكرًا literally = I put sugar in it
• natural English = I add sugar to it

Both ideas match the same real action.

If you want a verb closer to English add, Arabic also has:

• أضيف = I add

So you could also say:

• ولا أضيف إليه سكرًا

But أضع فيه سكرًا is completely natural.

Yes. Arabic word order is flexible.

These are both correct:

• في الصباح أشرب الحليب
• أشرب الحليب في الصباح

Starting with في الصباح gives the time first and sets the scene. That is why it appears at the beginning here.