"Bojíme se, abychom o ten strom nepřišli."

Translation: We are afraid of losing that tree.

[BoneheadBass]

Would someone please explain why the verb in this sentence is negative? A literal translation, even if it's weird, might help me understand what's going on with this one. Thanks!

[VladaFu]

It is probably a special kind of phrase. Literally: "so that we wouldn't lose the tree." Bát se and equivalents (mít strach, ...) just uses this with abychom.

Compare with: "Bojíme se, že přijdeme o ten strom.", which has the same or almost the same meaning.

Normally, abychom is used to express a purpose, but with these verbs it serves a different purpose.

Děláme to, abychom o ten strom nepřišli. We do that, so that we don't lose the tree.

[Renardo_11]

Maybe that could be compared to the (archaic, I believe) use of “lest” after the English “to be afraid.” (“…to be afraid lest we should sin.”)