The assertion that Esperanto is an easy language clearly needs qualification.

The obvious one is that this is true in comparison to the national languages.

But reading some of the recent posts here I see that perhaps an even more important one is, that whether it seems easy or not depends what you have been taught at school.

Has your education introduced you to basic grammatical concepts? If not then there is whole lot of stuff you have to master first (which you are likely to need in learning any foreign language.)

It is clear from any casual perusal of the famous 16 reguloj, that Zamenhof could comfortably assume in his 19th century audience a certain level of grammatical sophistication - which he could not assume today in a 21st century audience - at least in certain parts of the world.

Don't blame Esperanto. Blame modern education.

Actually, I wouldn't blame modern education.

I certainly got many years of grammar instruction from grades K-6 (after which the focus began to be placed on literature). But as I commented before, in another post, if you don't work in a field where technical grammar knowledge is necessary, then you forget the details as you get older. It's no different from how most of us don't remember much of what we learned in chemistry class, or how the specifics of Great Expectations are either extremely hazy or entirely forgotten.

The fact is that one need not remember how an adjective differs from an adverb, or how the past perfect tense differs from the future perfect continuous tense, to be speak and write in English. Through constant repetition and exposure from birth, the ability just becomes automatic. And so as we move into our later teens and then adulthood, few people who aren't grammar teachers or news editors continue to maintain a conscious technical knowledge of the particulars of the language.