> He said that if he could have chosen a language, instead of English, to be the world’s shared second language, then it would be Swahili or colloquial Indonesian.

I've learned Swahili to a basic conversational level and my experience learning the language mirrors the author's time picking up Esperanto. Grammatically, everything seems to make sense especially the simplicity of the verbs, and as a native English speaker you can pretty much pronounce/hear all the sounds from the jump. However, once you get deeper into the language you have to worry about the extreme amount of noun classes (think genders). In Swahili there are 8+ depending how you count them. These noun classes change the prefixes on the adjectives and verbs around them which can cause major confusion. I've always thought if they condensed these noun classes to 1 or 2 then Swahili would be the simplest language in the world.