Verb conjugation of "gâcher" in French

I would rather like that you write through the messaging system on this site and not to my private email address. All the info is gathered here online and I would like to keep is this way. It is nothing personal.
The idea is to use the sourcing to get as much information as possible about learning abilities and disabilities in average. This way we can determine and forecast best practices for language learners based on some parameters.
Thanks for the corrections and for accepting my friends request. You are completely right: Spanish grammar is simpler than German grammar. I was just looking for a job where both languages are required.