500
Quizás lo pueden hacer vs. Quizás lo puedan hacer
Explain the different translations and why they change based on conjugation.
What is Perhaps they can do it (and I'm sure of it.) vs. Perhaps they can do it (but I doubt it.)
Note: In a sentence such as this, the subjunctive is used to emphasize uncertainty or doubt, the indicative to emphasize certainly. Note how the Spanish verb form is used to indicate an attitude that might need further explanation in English.