"I don't like traveling alone."
Translation:Mi ne ŝatas vojaĝi sola.
I thought it would be "sole," since it's modifying "vojaĝi," but it's "sola." Why an adjective?
You can think of it as modifying "mi". (This is something called a "perverba priskribo" - you're describing the subject of the sentence, and the verb is giving you extra information about how the noun and adjective fit together.)
So basically, "sola" modifies "mi" because there is an infinitive meaning if it were "sole" it would be modifying "ŝatas" which would not make sense?
The form "sole" is here correct, too. But "sole" normally means "only". Therefore in the sense of "alone" the adjective form "sola(j)" is preferred as arbaro has explained it.
Just chiming in because there is a lot of discussion on this thread. I hope I can add some clarity rather than add to the confusion. Mostly I want to agree with Arbaro and Jxetkubo.
People who don't want to take my word for it can check PMEG and PIV, but basically both sola and sole can be correct, but my advice is to use sola to avoid ambiguity. Consider these examples from PMEG.
- Ili iris sole tien. = Ili iris nur tien.
- Ili iris solaj tien. = Ili iris tien sen akompano.
But before we get too hard and fast here, consider this Zamehofa example from PIV.
- malfeliĉo malofte venas sole
The explanation is that here it means that misfortune seldom comes unaccompanied or without outside help.
And another example from PIV looks similar but here sole means "only".
- li venos sole dimanĉe
And it's exactly because of this ambiguity that I suggest using sola in the original sentence we're discussing.
I think fair arguments can be made that either sola or sole can be used here. You can say that sola is describing mi, the subject of the sentence, or you can say that sole attaches to vojaĝi, essentially saying, "to travel in an alone kind of way."
This is one of these areas where language and thought gets somewhat murky, but using either sole or sola here will most likely communicate what it is meant.
To me, "alone" describes how you travel. How do you travel? I travel alone, or singly. Which is an adverb. Mi voyaĝas sole. I noticed that unuope was also listed in the choices, and it seems odd that unuope (an adverb) could be there, but not sole.
If "sola" is modifying "mi" then shouldn't the sentence mean "Only I don't like traveling" (but everyone else does like traveling)? How would "Only I don't like traveling" be rendered any differently from "I don't like traveling alone" on your interpretation?
There's no question that this is how everyone wants these words to work (or at least assumes that this is how the work). The problem is that according to Esperanto grammar, they ought to mean exactly the same thing, except that one of them should be an adjective (sola) and one of them an adverb (sole). Adjectives and adverbs are chosen according to what part of speech they're supposed to modify. "Sola" as an adjective would have to modify a noun or pronoun. But in the English sentence "alone" is not modifying a noun or pronoun, it's modifying a verb, that meaning and usage ought to require an adverb (sole). I think the problem is that people are translating words rather than recasting the thought in an Esperanto idiom under Esperanto logic.
Your last sentence... important guiding principle of learning a second language, that is so easy to forget! Should be emphasized by teachers.