Breakdown of O valor, como podes comprová-lo?
como
how
poder
can / may (verb)
-lo
it / him (m) [-la, -los, -las]
comprovar
to prove
Questions & Answers about O valor, como podes comprová-lo?
Why is O valor placed at the very beginning and separated by a comma?
This is a technique called left-dislocation or topicalization. By pulling O valor to the front, the speaker emphasizes it as the main topic of the question. In English, we do something similar when we say, "The value, how can you prove it?" instead of "How can you prove the value?"
Since we already mentioned O valor, isn't the -lo redundant?
It might feel redundant, but this is a standard feature of left-dislocation in Portuguese. When a direct object like O valor is pulled to the front of the sentence, we usually need a "resumptive pronoun" (in this case, the clitic -lo) attached to the verb to act as a grammatical placeholder for it.
Why does the verb become comprová-lo with an accent, rather than just comprovar-o?
When a direct object pronoun like o, a, os, or as attaches to a verb ending in -r, -s, or -z, that final consonant is dropped and the pronoun gains an L (becoming -lo). Because dropping the -r from comprovar removes the visual cue for where the spoken stress falls, we must add an acute accent to the final a (comprová) to maintain the correct pronunciation.
Since como is a question word, could I pull the pronoun forward and say como o podes comprovar?