Breakdown of Siempre usa los lentes al forjar, no sea que una chispa te dañe el ojo.
ser
to be
no
no, not
una
a, an (feminine)
siempre
always
Questions & Answers about Siempre usa los lentes al forjar, no sea que una chispa te dañe el ojo.
Why is dañe in the subjunctive here?
The phrase no sea que means 'just in case' or 'lest' (expressing a precaution to avoid a negative outcome). It always triggers the subjunctive because it introduces a hypothetical situation you are trying to prevent. Therefore, the verb dañar takes its present subjunctive form, dañe.
Why does the sentence use al forjar instead of something like cuando forjas?
Al followed by an infinitive (like forjar) is a very common and natural way to say 'when doing something' or 'upon doing something'. While cuando forjas is also grammatically correct, al forjar is concise and highly idiomatic in Spanish.
Why does it say te dañe el ojo instead of dañe tu ojo?
In Spanish, when an action affects a body part, you typically avoid possessive adjectives (like tu). Instead, you use an indirect object pronoun to show who is affected (here, te) and a definite article for the body part (here, el). It literally translates closer to 'damages the eye to you'.