"Are you fixing the lamp?"
Translation:Korjaatteko te lamppua?
Question 1 : would it be preferable to translate "Korjaatko lamppua?" by "Are you fixing a lamp?" (i.e., the indefinite "a" instead of the definite "the")? Question 2 (related to the first question): I understand that the letter "a" at the end of lamppua signals the partitive case. However, I do not understand whether it is used to refer to an immediate (i.e., an ongoing) action or to an indefinite thing (i.e., a lamp instead of the lamp).
In "korjaatko lamppua?" the lamp can be translated either as "a lamp" or "the lamp".
To your second question, the partitive is used there more to signal an ongoing action, but with the genitive -n ending the "lamppu" would certainly also be more definite.
"Korjaatko lamppua?" - Are you fixing a/the lamp?
"Korjaatko lampun?" ~ do you intend to fix the lamp?