Learn Hardcore Spanish (Spain): Gira en la rotonda y sigue por el carril derecho. - Turn at the roundabout and stay in the right lane.

gira = tú imperative of girar
sigue = tú imperative of seguir (irregular stem change) Polite and plural alternatives:
gire / siga (usted, formal singular)
girad / seguid (vosotros/as, Spain informal plural)
giren / sigan (ustedes, formal plural in Spain; default plural in Latin America)

Would a GPS or a road sign in Spain use gira or gire?

Both occur, but formal instructions (signs, official announcements, many GPS voices) often use the polite usted, so you’ll see/hear gire and siga. Informal contexts (a friend giving directions) often use gira and sigue.

Why is it en la rotonda? In English we say “at the roundabout.”

Spanish uses en for several English prepositions: in/on/at. With places like roundabouts, intersections, corners, etc., en is standard: en la rotonda, en el cruce, en la esquina.

Why por el carril derecho and not en el carril derecho?

Both are possible, with a slight nuance:

seguir por emphasizes the route/path you travel along (along the right lane).
seguir en emphasizes remaining/staying in that lane (stay in the right lane). In practice, you’ll hear both. Your sentence focuses on the route.

Could I leave out the preposition and say sigue el carril derecho?

Yes. Seguir can take a direct object: sigue el carril derecho = “follow the right(-hand) lane.” Using por is also very common and natural.

Why derecho and not derecha?

derecho here is an adjective modifying carril (masculine): carril derecho = “right-hand lane.”
a la derecha uses the noun derecha (“the right side”) and is used for turning direction: gira a la derecha. Note: In Spain, “straight ahead” is usually (todo) recto, not derecho. In parts of Latin America, sigue derecho = “go straight.”

Is carril de la derecha also correct?

Yes. el carril derecho and el carril de la derecha are both idiomatic. The first treats “right” as an adjective; the second says “the lane on the right.”

What does carril mean exactly? Is it the same as calle?

carril = a lane (one of the longitudinal divisions of a road).
calle = a street (the whole roadway).
calzada = the carriageway/roadway (where vehicles drive).
vía = a generic “way/route,” context-dependent.

Is rotonda the normal word in Spain? What about glorieta?

Yes, rotonda is the most common in Spain. glorieta also exists (and appears on some signs) but is less common in everyday speech. Elsewhere you may hear redondel, óvalo, or glorieta, depending on the country.

Does gira en la rotonda mean “turn at the roundabout” or “take a specific exit”?

By itself, it’s general: “turn at the roundabout” (i.e., enter and make your turn there). To be precise about exits, Spanish says: En la rotonda, toma la segunda salida, etc.

How would I say it if the idea were to change lanes to the right?

Use a/al with a motion verb:

cámbiate al carril derecho
pásate al carril derecho
colócate en el carril derecho These mean “move over to the right(-hand) lane.”

Can I reorder it as En la rotonda, gira y sigue por el carril derecho?

Yes. Fronting en la rotonda and adding a comma is natural and common: En la rotonda, gira y sigue por el carril derecho.

Do the articles matter? Could I say Gira en rotonda or sigue por carril derecho?

You need the articles. Natural Spanish is en la rotonda and por el carril derecho. Omitting them sounds telegraphic or ungrammatical in this context.

Any pronunciation tips for the tricky parts?

gira: In Spain, gi- sounds like a throaty H (rough J): approx. “HEE-ra.”
sigue: The u is silent; say “SEE-geh” (not “see-gway”).
carril: rr is a strong roll: “ka-RRIL.”
derecho: ch = “ch” in “church”: “de-RE-cho.”
rotonda: Soft intervocalic d (often like a soft “th” in “this”): “ro-TON-da.” Stress: gi-RA, SI-gue, ca-RRIL, de-RE-cho, ro-TON-da.

What are the negative command forms?

no gires (tú), no gire (usted), no giréis (vosotros), no giren (ustedes)
no sigas (tú), no siga (usted), no sigáis (vosotros), no sigan (ustedes)

Could I use other verbs instead of girar and seguir?

Yes:

Spain: girar, also torcer (colloquial/regional). For “continue”: seguir or continuar.
Latin America: doblar, voltear for “turn,” and seguir/continuar for “continue.” In Spain, doblar/voltear for “turn” is uncommon.

Does rotunda exist in Spanish, and is it the same as rotonda?

They’re different words. rotonda = roundabout. rotunda (with a U) means “categorical/unequivocal” (an adjective), not the traffic circle.