Variations in the uſe of aſpects and tenſes preſent ſimilar problems acroſs almoſt any two languages that are not cloſe ſiſters.. The Romans faced that with learning Greek. I would think the biggeſt problem with Engliſh would be the totally chaotic orthography, but that would always be the biggeſt problem with Engliſh, no mater what the ſtudent's first language.