Don't forget about irregular verbs. The only way to learn them is by heart.
As for Spanish, it's also a very tough language. Each verb has about 30 conjugations, 12 rules to determine where
accents go, 100 spelling rules... maybe what's easy is the pronunciation, because most letters have always the same
pronunciation: the R, for example, is a Japanese R between 2 vowels, and a Russian R when not between vowels, or when
you find a "rr" between 2 vowels (like "encerar" and "cerrar"... see?). To make yourself
an idea, they teach it until the first 2 half years of high school.
By the way, now that I mentioned high school, Mexico's educational levels are these:
~ 3 years of "preescolar", kindergarten, starting from age 3.
~ 6 years of "primaria", or elementary, starting from 6.
~ 3 years of "secundaria", or high school, starting from 12. There's no middle school here.
~ 3 years of "preparatoria", or college, starting from 15.
~ 4-5 years of university, starting from age 18.
~ 2-3 years of master after you clear the university.
~ 2-3 years of Ph. D once you clear the master.
College comes here in 3 flavors:
* General: straightforward, all-around, normal college education.
* Technical: you skip the university and get your professional technician title.
* Specialized: you choose an area. Subjects, at least in my school, are 4 standard and 4 different: physics,
programming, drawing and philosophy for engineers; health, chemistry, psychology and epistemology for medics and
biologists; management, programming, economy and philosophy for managers; laws, literature, epistemology and psychology
for human sciences. This leads to something interesting: math and physics are so shunned by students, they stay away
from the engineering group, and enter the human science groups, even if they have to read 100 weekly pages written by
people under heavy drugs; to them, that's a small price to pay for less math and no physics.