Questions & Answers about Pewnie kupiłbym wyspę i idealny dom.
How do we build the conditional word kupiłbym?
You build it by taking the third-person masculine past tense of the verb (kupił - he bought) and adding the conditional ending for the first person (-bym).
If a woman were speaking, how would she say "I would buy"?
Because the conditional mood is built on the past tense, it changes based on gender. A woman would use the feminine past tense (kupiła) and add the same ending, making it kupiłabym.
Why doesn't idealny dom change its ending here, while wyspę does?
Both are direct objects, so they need to be in the accusative case. Wyspa is a feminine noun, so its ending changes to -ę. However, dom is a masculine inanimate noun. For these nouns, the accusative case looks exactly the same as their basic dictionary form.
I thought pewnie meant "certainly" or "surely." Why is it translated as "probably"?
Even though it comes from the adjective pewny (certain), in everyday spoken Polish, pewnie is very commonly used to mean "probably." In hypothetical daydream sentences like this one, it almost always means "probably."