How do I review a translation in a language I don't speak? 

You cannot judge whether it reads well, but you can check more than you think, and you can tell whether it says what the source says.

Check what is mechanical first. Most translation defects that reach users are not language problems: a dropped placeholder, a translated variable name, a missing plural form, a text that overflows its button. Run the QA checks and look at the length counters. These catch errors in any language without reading it.

Check the meaning with a back-translation. A literal translation back into your language shows whether the sentence kept its meaning, its numbers and its negations. Free machine translation works for this, with one rule: compare meaning, not wording. "Start your free trial now" coming back as "Begin the free test now" is fine; coming back as "Your free trial has started" is not. In Localizely the Explain action of the AI Assistant does this in the editor and also points out tone shifts, missing placeholders and length problems.

Check terminology. If your product calls it a "workspace", every language should use one word for it. A glossary with the approved term per language lets you check this without speaking the language: search the translation for the glossary term.

Check it in context. Screenshots show whether a translation fits the screen and matches the element it labels. A string that is correct in isolation can still be wrong for a button.

Know what you cannot check. Naturalness, register and idiom need a native speaker. Mark those translations as reviewed only for what you verified, and send the rest to a translator or to a colleague who speaks the language. One native read of a hundred strings catches what no tool does.