Learn Hardcore Spanish (Spain): Mi hermana gira a la derecha, pero mi hermano gira a la izquierda. - My sister turns right, but my brother turns left.

With the explicit subject (Mi hermana / mi hermano), gira is the present indicative, 3rd person singular: “she/he turns.” Without a subject, Gira a la derecha can also be the affirmative command for tú (“Turn right”). The formal command is gire (usted), and in Spain the plural informal command is girad (vosotros).

Why is it a la derecha/izquierda and not just a derecha/izquierda?

Because derecha and izquierda are used as nouns here (“the right/left side”), and in Spanish you normally include the definite article: a la derecha, a la izquierda. Dropping the article is not standard in everyday speech; you might only see it in very telegraphic contexts (e.g., on signs).

Does the feminine form (derecha/izquierda) agree with hermana?

No. Derecha and izquierda are feminine because they’re nouns that are inherently feminine, not because they agree with hermana. They would still be feminine with a masculine subject: Mi hermano gira a la derecha.

Could I say derecho instead of derecha?

Not for “to the right.” Derecho as an adjective means “right” for masculine nouns (e.g., ojo derecho) and as an adverb in some regions means “straight,” but in Spain “straight ahead” is usually todo recto. For turning right/left, use a la derecha / a la izquierda.

Is the comma before pero necessary?

Yes. When pero connects two clauses, Spanish normally places a comma before it: …, pero …. Your sentence’s comma is correct.

When would I use sino instead of pero?

Use sino after a negation to mean “but rather.” For example: No gira a la derecha, sino a la izquierda. If you repeat a verb, use sino que: No gira a la derecha, sino que gira a la izquierda. In your original (no negation), pero is the right choice.

Are there other common verbs for “to turn” in Spain?

Yes:

girar (very common, neutral)
torcer (also common: Mi hermana tuerce a la derecha)
For giving directions, Spaniards also say coger/tomar (e.g., Coge/Toma la segunda a la derecha). Note: coger is standard in Spain but vulgar in parts of Latin America.
doblar is more typical in Latin America than in Spain.

How do I say this as a command when giving directions?

Informal (tú): Gira a la derecha.
Formal (usted): Gire a la derecha.
Plural informal (vosotros, Spain): Girad a la derecha.
Plural formal (ustedes): Giren a la derecha.

Can I leave out the second gira to avoid repetition?

Yes: Mi hermana gira a la derecha; mi hermano, a la izquierda. The semicolon (or a comma with proper context) plus the comma after mi hermano shows the verb is elided.

What’s the difference between a la izquierda and a la izquierda de?

a la izquierda = the direction “to the left.”
a la izquierda de + noun = “to the left of [something]”: a la izquierda del semáforo (“to the left of the traffic light”).

Can I use en with girar?

Yes, to mark the place where the turn happens: Gira a la derecha en la calle Mayor (“Turn right on Main Street”). Use a for the direction and en for the location.

How do I make it plural if both siblings turn?

Use a plural subject and verb: Mi hermana y mi hermano giran a la derecha. Note the verb changes to giran (3rd person plural).

Why is it mi without an accent? Isn’t there mí with an accent?

mi (no accent) is the possessive adjective “my” (mi hermana, mi hermano). mí (with accent) is the prepositional pronoun “me” after prepositions: para mí, de mí.

How do Spaniards actually pronounce these words?

gira: in Spain, g before i sounds like the j in Spanish, a throaty “h”: [ˈxiɾa].
derecha: [deˈɾet͡ʃa].
izquierda: in most of Spain, z = “th” sound: [iθˈkjeɾða]. The u in -quie- is silent. In Latin America, the z is pronounced like s.

Is word order flexible? Could I say Gira a la derecha mi hermana?

It’s possible (verb–subject inversion exists in Spanish), but here it would sound marked or literary. The neutral order is the one you have: Mi hermana gira a la derecha.

Is there any nuance difference between girar and something like dar la vuelta?

Yes. girar (or torcer) is “to turn” right/left at a point. Dar la vuelta usually means “to turn around/ make a U-turn” or “to go around.” Don’t use dar la vuelta for a simple right/left turn.

Are there standard abbreviations for derecha and izquierda in Spain (e.g., in addresses)?

Yes: dcha. for derecha and izda. for izquierda. For example, 3.º dcha. = “3rd floor, right.”