Mi hermana estudia geografía, igual que mi prima.

In modern standard Spanish, possessive adjectives like mi, tu, su, nuestro normally go directly before the noun without an article:

• mi hermana = my sister
• mi prima = my cousin

So mi hermana is the normal way to say my sister. Using la mi hermana is not standard modern Spanish.

Estudia is the third-person singular present tense form of estudiar.

The subject is mi hermana, which is she, so the verb must match:

• yo estudio = I study
• tú estudias = you study
• él/ella estudia = he/she studies

So Mi hermana estudia geografía means My sister studies geography.

Spanish often omits subject pronouns because the verb ending already shows who is doing the action.

So instead of saying:

• Ella estudia geografía

Spanish very naturally says:

• Mi hermana estudia geografía

or simply:

• Estudia geografía

if the context is clear.

Including ella is possible, but it usually adds emphasis, contrast, or clarity.

Here, igual que means just like or the same as.

So:

• Mi hermana estudia geografía, igual que mi prima.

means:

• My sister studies geography, just like my cousin.

It compares your sister with your cousin and says they both study geography.

Spanish often leaves out repeated words when the meaning is obvious.

So instead of saying:

• Mi hermana estudia geografía, igual que mi prima estudia geografía

Spanish normally shortens it to:

• Mi hermana estudia geografía, igual que mi prima

The missing part is understood from the first clause. English does this too sometimes, as in My sister studies geography, just like my cousin.

Yes, you could, but it sounds more explicit and is less natural in a simple sentence like this.

• igual que mi prima = the most natural, concise version
• igual que mi prima lo hace = more emphatic or stylistically fuller

In everyday Spanish, the shorter version is usually preferred when the meaning is already clear.

Prima means female cousin.
The masculine form is primo, meaning male cousin.

So:

• mi prima = my female cousin
• mi primo = my male cousin

Unlike English, Spanish usually marks this gender difference in the noun itself.

The accent mark in geografía shows where the stress falls: ge-o-gra-FÍ-a.

Without the written accent, standard Spanish stress rules would suggest a different pronunciation. The accent helps show the correct stressed syllable.

It also helps learners pronounce the word correctly.

In Spain, a common pronunciation is approximately:

• heh-oh-grah-FEE-ah

More specifically:

• the g before e sounds like a strong Spanish j sound
• the fí syllable is stressed
• the final a is clearly pronounced

In much of Spain, if you hear geografía said naturally, the g sound is quite different from the English g in geography.

No. You could also say:

• Mi hermana estudia geografía, como mi prima.

That also means My sister studies geography, like my cousin.

But igual que often feels a bit more like the same as or just like, so it works very well in this sentence.

After the verb estudiar, Spanish often uses the subject of study without an article:

• Estudia geografía
• Estudia medicina
• Estudia historia

This is similar to English, where we usually say study geography, not study the geography.

Yes. The Spanish present tense often covers both ideas, depending on context:

• Mi hermana estudia geografía can mean
  • My sister studies geography
  • My sister is studying geography

If you need to be extra clear about an action happening right now, Spanish can also use:

• Mi hermana está estudiando geografía

But the simple present is very common and natural.