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"Llegar" is an intransitive verb which is often translated as "to arrive", and "regresar" is an intransitive verb which is often translated as "to return". Learn more about the difference between "llegar" and "regresar" below.
llegar(
yeh
-
gahr
)An intransitive verb is one that does not require a direct object (e.g., The man sneezed.).
b. to get 
Voy a llegar al restaurante un poco atrasado.I am going to get to the restaurant a little late.
f. to be there  (moving away)
No saben decir a qué hora llegarán.They're not sure what time they'll be there.
a. to be enough 
No me llega el sueldo, así que voy a pedir un aumento.My salary is not enough, so I'm going to ask for a raise.
d. to come to 
Con la información provista, demuestra cómo llegaste a tu conclusión.With the information provided, please show how you came to your conclusion.
a. to reach 
El precio del barril de Brent llegó a los 100 dólares.The price of a barrel of Brent reached 100 dollars.
a. to come to 
Obama llegó a la Casa Blanca a principios de 2009.Obama came to the White House at the beginning of 2009.
a. to come up to 
Después del aguacero, el agua me llegaba a la rodilla.The water came up to my knees after the downpour.
c. to touch 
No me gustan las faldas que llegan hasta el piso.I don't like skirts that touch the floor.
a. to go as far as 
El Camino de Santiago llega hasta el extremo oeste de España.The Camino de Santiago goes as far as the far west of Spain.
12. (to hold up)
a. to last 
Ojalá estas llantas me lleguen otras cien mil millas.Hopefully, these tires will last me another hundred thousand miles.
a.  no direct translation
This refers to an idiomatic word or phrase for which there is no word-for-word translation.
Si llego a saber que tendrían nuevos episodios, no hubiera cancelado mi membresía.Had I known that they were going to have new episodes, I never would have cancelled my membership.
Si llegaras a ir al restaurante, tienes que probar la tarta de fresa.If you end up going to the restaurant, you must try the strawberry tart.
llegarse
A pronominal verb always uses a reflexive pronoun. (e.g., Te ves cansado.).
a. to go over to  (moving away)
Llégate a casa de Rosa y pídele una taza de azúcar.Go over to Rosa's house and ask her for a cup of sugar.
b. to go round to  (moving away) (United Kingdom)
Regionalism used in the United Kingdom
Llégate a la tienda y cómprame leche, por favor.Go round to the shop and buy me some milk, please.
c. to come over to  (approaching)
Llégate a casa de mi hermana mañana y nos pasamos un rato.Come over to my sister's house tomorrow and we can spend some time together.
e. to come around to  (approaching)
¿Por qué no te llegas al estudio el sábado e improvisamos un rato?Why don't you come around to the studio on Saturday and we can jam a while?
f. to come round to  (approaching) (United Kingdom)
Regionalism used in the United Kingdom
Llégate al bar una tarde y tomamos algo.Come round to the bar one evening and we can have a drink.
a. to go up to 
Me llegué a ella y le pedí un autógrafo.I went up to her and asked her for an autograph.
regresar(
rreh
-
greh
-
sahr
)An intransitive verb is one that does not require a direct object (e.g., The man sneezed.).
a. to return 
Regresa con la factura si quieres un crédito de la tienda.Return with the receipt if you want store credit.
c. to go back 
Solo llevo una semana de vuelta, pero ya quiero regresar a España.I've only been back a week and I already want to go back to Spain.
A transitive verb is a verb that requires a direct object (e.g., I bought a book.).
2. (to hand back) (Latin America)
Regionalism used in Latin America: all the countries in South America, Central America, and the Caribbean. Does not include Spain.
a. to return 
Tendrás que regresar el vestido si no te sirve.You'll have to return the dress if it doesn't fit.
b. to give back 
Regrésale los libros cuando termines con ellos.Give the books back to him when you've finished with them.
regresarse
A reflexive verb is a verb that indicates that the subject performs an action on itself (e.g., Miguel se lava.). 
3. (to be back) (Latin America)
Regionalism used in Latin America: all the countries in South America, Central America, and the Caribbean. Does not include Spain.
a. to return 
Se regresaron después de dos meses de estar perdidos. They returned after two months of being missing.