Kono sagyō o ichinichi de owaraseru no wa fukanō desu.

It is impossible to finish this work in one day.

Kagakuteki ni ieba, sono keikaku wa fukanō ni chikai.

Scientifically speaking, that plan is close to impossible.

Kare wa doryoku ni yotte fukanō na koto o kanō ni dekiru to shōmei shita.

He proved that the impossible can be made possible through effort.

Yosan ga nakereba, kono purojekuto no jikkō wa jijitsujō fukanō da.

Without a budget, executing this project is virtually impossible.

Saisho kara fukanō da to kimetsukete akiramete wa ikenai.

You must not give up, assuming from the start that it is impossible.

Kako ni modoru koto wa butsuri teki ni fukanō desu.

Going back to the past is physically impossible.