Three things to know, three minutes to learn: full-page translation, select-to-translate, and bilingual YouTube subtitles.
Translate an entire page in place, with the layout left intact.
Nothing to configure after installing — just open the page you want to read.
You can also press Alt+Q, or right-click the page and choose “Translate this site” — all three do the same thing.
Trigger it again to switch back. The site is remembered, so it translates automatically next time you visit.
When you only need one sentence, selecting it is enough.
On any foreign-language page, drag-select the sentence you cannot read, just as you normally would.
After about 0.3 seconds the translation appears right below your selection — no button to click.
In the extension settings you can disable select-to-translate, or require a tap of Alt after selecting.
Original and translated lines shown together while you watch.
Click the CC button in the player to confirm the video has a subtitle track.
It sits in the control bar at the bottom right of the player, next to CC.
Bilingual stacks the original above the translation; pick the second option for translation alone. You can switch it off any time.