"It is not worth much."
Translation:No vale mucho.
To be worth - Valer is a verb. Even if you wanted to use ser or estar in front of it, you wouldn't use the conjugated form of valer, but instead you'd use the infinitive. However this is also incorrect because it's vale itself means It/he/she/you "has/is worth" since it's meaning is "to be worth". There are a few verbs like this, be careful.
English sentences require a subject. When the subject isn't otherwise stated, we default to using the "dummy subject", the pronoun 'it'.
Spanish does not do this. If the subject isn't stated, it's assumed to be implied. This means that 'lo' is used exclusively as an object pronoun (that which the verb is acting upon, rather than that which is performing the action).
This is why English says "It is raining", while Spanish says "Llueve". Or, "It isn't worth much" as opposed to "No vale mucho". The 'it' doesn't stand for anything in English, and Spanish just leaves it out entirely.
If I wanted to use 'lo' here, I might restate the sentence as "No lo valgo mucho", which would mean that I don't value it highly. Note that 'lo' has become the object of the sentence, that which is being valued, while the subject is the implied 'yo'.
I hope this helped. Cheers.
I think you mean indefinite pronoun, and even that wouldn't be right.
Spanish doesn't really have a subject pronoun for it (unless you count, ello, but it's only used in rare cases). Lo is a direct object pronoun. A direct object pronoun answers who or what the verb is action on. The above sentence doesn't have a direct object.
Just so anyone else may know, my answer was: "No tiene mucho valor." and was counted as correct. I guess I was thinking along the same line as "tiene años" for expressing one's age, or "tiene miedo" for being afraid. Would this be an odd or particularly inferior expression of the idea of value to a native speaker?