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"Alone" is an adverb which is often translated as "solo", and "by themselves" is an adjective which is often translated as "solos". Learn more about the difference between "alone" and "by themselves" below.
alone(
uh
-
lon
)
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g. to run quickly, very tired).
adverb
1. (by oneself)
a. solo
I don't feel comfortable when I'm home alone.No me siento cómodo cuando estoy en casa solo.
b. a solas
We were alone after dinner.Estuvimos a solas después de la cena.
2. (only)
a. solo
Your parents alone can give you permission.Solo tus papás te pueden dar permiso.
b. solamente
You alone know what decision will make you happy.Solamente tú sabes qué decisión te hará feliz.
3. (by oneself)
a. solo
He likes to work alone.Le gusta trabajar solo.
An adjective is a word that describes a noun (e.g. the big dog).
adjective
4. (by oneself)
a. a solas
We were alone after dinner.Estuvimos a solas después de la cena.
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by themselves(
bay
 
thehm
-
sehlvz
)
An adjective is a word that describes a noun (e.g. the big dog).
adjective
1. (alone)
a. solos
The kids are by themselves in the house.Los niños están solos en la casa.
An adverb is a word that describes a verb, an adjective, or other adverbs (e.g. to run quickly, very tired).
adverb
2. (alone)
a. solos
My cousins are old enough to drive by themselves.Mis primos tienen la edad suficiente para manejar solos.
b. a solas
Are the kids playing outside by themselves?¿Los niños están jugando afuera a solas?
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