Sie trinkt Wein.

This is one of the most common German learner questions.

Sie with a capital S can mean formal you.
sie with a lowercase s can mean she or they.

So:

• sie trinkt Wein = she drinks wine
• Sie trinken Wein = you drink wine (formal, singular or plural)

In your sentence, Sie trinkt Wein, the verb is trinkt, which is the third-person singular form. That matches she, not formal you.

So in normal grammar, this sentence means she drinks wine.
If you saw Sie capitalized at the beginning of a sentence, that does not automatically mean formal you, because the first word of every sentence is capitalized anyway. You have to look at the verb form to tell.

Because the verb has to agree with the subject.

The infinitive is trinken = to drink.

For she (sie), German uses the third-person singular form:

• ich trinke = I drink
• du trinkst = you drink
• er/sie/es trinkt = he/she/it drinks
• wir trinken = we drink
• ihr trinkt = you all drink
• sie/Sie trinken = they / formal you drink

So Sie trinkt Wein uses trinkt because the subject is she.

German often leaves out the article with uncountable nouns or when speaking in a general sense.

Wein is being used here a bit like wine in English:

• She drinks wine.

You could also say:

• Sie trinkt einen Wein.

But that usually means she is drinking a wine or a glass/order of wine, which sounds more specific and less neutral.

So Sie trinkt Wein is the normal way to say that she drinks wine in general or is drinking wine.

Because all nouns are capitalized in German.

So:

• der Wein = the wine
• das Buch = the book
• die Frau = the woman

This is a basic spelling rule in German.
Even in the middle of a sentence, nouns begin with a capital letter.

Wein is in the accusative case, because it is the direct object of the verb trinkt.

The sentence structure is:

• Sie = subject
• trinkt = verb
• Wein = direct object

With a masculine noun like der Wein, the accusative article would be den:

• Sie trinkt den Wein. = She drinks the wine.

But since there is no article in your sentence, the noun itself stays just Wein. You do not see a special accusative ending on the noun here.

This is standard German main-clause word order: subject + verb + object.

German often looks similar to English in simple statements:

• She drinks wine.
• Sie trinkt Wein.

The important rule is that in a main clause, the conjugated verb usually comes in second position.

Here:

1. Sie
2. trinkt
3. Wein

That is perfectly normal German word order.

Yes, but it changes the emphasis.

Wein trinkt sie is possible in German, but it sounds marked or contrastive, something like:

• Wine is what she drinks
• She drinks wine (not something else)

This happens because German allows more flexibility in word order than English, as long as the finite verb stays in the correct position in a main clause.

The neutral, default sentence is still:

• Sie trinkt Wein.

German simple present (Präsens) can express both ideas, depending on context.

So Sie trinkt Wein can mean:

• She drinks wine = habit / general fact
• She is drinking wine = right now

German does not use a form exactly like English is drinking nearly as often. Usually, context tells you which meaning is intended.

For example:

• Normalerweise trinkt sie Wein. = She usually drinks wine.
• Gerade trinkt sie Wein. = She is drinking wine right now.

A simple English-friendly guide would be:

• Sie ≈ zee
• trinkt ≈ trinkt with a short i
• Wein ≈ vine

More roughly:

• zee trinkt vine

A few notes:

• ie in Sie sounds like a long ee
• w in German sounds like English v
• ei in Wein sounds like English eye or i in vine

So Wein sounds close to vine, not like English wane or ween.

Mostly yes.

Trinken is a strong verb in some forms, but in the present tense it behaves quite predictably:

• ich trinke
• du trinkst
• er/sie/es trinkt

In the past tense, however, it changes its vowel:

• trank = drank
• getrunken = drunk

So for a beginner, it is fine to think:

• present tense: fairly straightforward
• past forms: need to be memorized

Not with trinkt.

If sie means they, the verb must be plural:

• sie trinken Wein = they drink wine

Since your sentence has trinkt (singular), it cannot mean they drink wine.

So with this verb form, the sentence means she drinks wine.