Zij is de derde student.

It can mean either in Dutch, but here it means she because the verb is is, which is singular.

• Zij is = she is
• Zij zijn = they are

So the verb form tells you which meaning is intended.

Both can mean she in this kind of sentence.

• ze is the more common unstressed form in everyday speech
• zij is the stressed or fuller form, and is also common in writing

So both Zij is de derde student and Ze is de derde student are possible, but zij can sound a bit more emphatic or formal.

It is capitalized only because it is the first word of the sentence.

In the middle of a sentence, it would normally be written zij, not Zij.

Because Dutch main clauses usually follow the verb-second rule, often called V2.

That means the finite verb comes in the second position:

• Zij is de derde student.
• Vandaag is zij de derde student.

Even when another element comes first, the verb still stays in second position.

In Dutch, ordinal numbers such as eerste, tweede, and derde usually come before the noun, just like adjectives.

Examples:

• de eerste dag = the first day
• de tweede keer = the second time
• de derde student = the third student

So the word order here is normal Dutch word order.

Because drie means three, while derde means third.

• drie = cardinal number
• derde = ordinal number

Dutch usually forms ordinals with -de or -ste, but drie becomes derde, not driede.

A few common ones are:

• een → eerste
• twee → tweede
• drie → derde
• vier → vierde

Because Dutch normally uses the definite article with ordinal numbers when you mean a specific one in a sequence.

So:

• de derde student = the third student

This works much like English.

If you said een derde student, that would usually mean a third student or another student making three, not the third student in an ordered list.

Because student is a de-word in Dutch.

So in the singular, you say:

• de student

Not:

• het student

This is something you mostly just have to learn with each noun.

Yes. In modern Dutch, student is very commonly used for a person of any gender.

So Zij is de derde student is perfectly normal for a woman.

There is also a feminine form, studente, but many speakers simply use student for everyone unless they specifically want to emphasize that the person is female.

Not always. In Dutch, student usually refers to someone in higher education, such as a university or college student.

For a school pupil, Dutch often uses leerling instead.

So depending on context:

• student = college/university student
• leerling = school pupil

This is an important difference from English.

Usually no. De derde student normally means the student who is third in order.

If you want to say third-year student, Dutch more naturally says:

• een derdejaarsstudent
• een student in het derde jaar

So de derde student is about position in a sequence, not about year level.