La farmacia está justo enfrente del colegio de mi hija.

Because this sentence talks about location, and Spanish normally uses estar for where something is.

• La farmacia está... = the pharmacy is located...
• ser is usually for identity, description, origin, etc.

So:

• La farmacia está enfrente... = correct for location
• La farmacia es enfrente... = not natural/correct here

Here justo means right or exactly.

So justo enfrente means:

• right opposite
• directly across from

It adds emphasis. Without it, La farmacia está enfrente del colegio de mi hija is still correct; it just sounds a little less precise.

Enfrente de means opposite or across from.

When it is followed by a noun, it normally uses de:

• enfrente del colegio
• enfrente de la estación

If no noun follows, you can often say simply:

• La farmacia está enfrente. = The pharmacy is opposite / across the street.

So in this sentence, de is needed because enfrente is followed by el colegio de mi hija.

Because de + el contracts to del in Spanish.

So:

• de + el colegio → del colegio

This is mandatory in normal Spanish.

A useful comparison:

• del = de + el
• al = a + el

But there is no contraction with la:

• de la farmacia = correct
• not dela

Spanish does not use an apostrophe 's the way English does.

Instead, possession is often expressed with de:

• el colegio de mi hija = my daughter’s school
• literally: the school of my daughter

This is one of the most common possession patterns in Spanish.

Spanish uses definite articles very often, especially when talking about specific places that are known in context.

Here:

• La farmacia = the pharmacy
• el colegio de mi hija = my daughter’s school / the school of my daughter

Even where English sometimes uses no article or a possessive more directly, Spanish often prefers the article.

No. In Spain, colegio usually means school, especially a primary school, though in everyday speech it can refer more generally to a child’s school.

For an English speaker, this is a false friend:

• colegio ≠ college
• college is more often universidad or sometimes another institution depending on context

So in this sentence, colegio should be understood as school, not college.

Yes. Frente a and enfrente de can both mean opposite / across from.

So these are both natural:

• La farmacia está enfrente del colegio de mi hija.
• La farmacia está frente al colegio de mi hija.

In many contexts they mean essentially the same thing. A learner should understand and be able to use both.

This is a very common confusion.

• enfrente de = opposite / across from
• delante de = in front of

So:

• La farmacia está enfrente del colegio = The pharmacy is across from the school.
• La farmacia está delante del colegio = The pharmacy is in front of the school.

These are not the same image. Enfrente suggests two things facing each other, usually on opposite sides of a street or space. Delante suggests one thing is positioned in front of another.

Because mi is the normal possessive adjective used before the noun:

• mi hija = my daughter

Mía is a different form, usually used:

• after the noun for emphasis: una hija mía
• or on its own: Es mía.

So:

• mi hija = correct here
• mía hija = not correct
• hija mía is possible in other contexts, but it has a different tone and is not the neutral form used here

The most natural order here is:

• La farmacia está justo enfrente del colegio de mi hija.

You can sometimes move parts around for emphasis, but not every change sounds natural. For example:

• La farmacia está enfrente del colegio de mi hija. = fine
• Justo enfrente del colegio de mi hija está la farmacia. = possible, more literary or emphatic
• La farmacia está enfrente justo del colegio... = much less natural

So for everyday Spanish, keep justo directly before enfrente.

A few useful pronunciation points:

• h is silent in Spanish: hija starts with the vowel sound
• j is pronounced like a strong breathy sound, similar to the ch in Scottish loch or the h in some pronunciations of José
• gi here sounds roughly like hee
• So hija sounds approximately like EE-ha with the stress on the first syllable

Also:

• farmacia = far-MA-cia
• colegio = co-LE-gio
• enfrente = en-FREN-te

Yes. The sentence is still completely correct without it:

• La farmacia está enfrente del colegio de mi hija.

Adding justo simply makes it more specific or emphatic:

• justo enfrente = right across from

So justo is optional, but useful.

Yes, if the place you are opposite from is already understood.

For example:

• ¿Dónde está la farmacia?
• Está enfrente.

But if you want to say opposite the school, you usually add de:

• Está enfrente del colegio.

So:

• enfrente alone = possible
• enfrente de + noun = needed when you name the reference point