English is also less weird than French, written English is pretty easy language. Spoken English not so much. Italian is perhaps much easier, but of course economic and social capital matters too.
I also agree with the economic and social capital argument.
I learn Spanish and Portuguese and I'm not the slightest confused by the gender rules - it's rather what I'm used to, since I speak German as native language.
TLDR: YMMV, but I don't think this holds if you come from a non-English background.
Gender and tense questions make a lot of things really complicated! There are only two tenses in english, really. Compare to Spanish/French conjugations, or German declination questions.
(Because this is HN) in a way, English ends up being very LISP-y (more CL than Scheme though). There are very few base constructs, and some special vocabulary, but most "grammar" is really just vocabulary. Future tense isn't a tense, it's using 'will'.
There's hardness because of all the dialects, and particles. Though I don't really know of a language where particle use isn't of a similar difficulty.
For example (I will use examples from German, since this is my native language) typical rules (probably you will find exceptions) are that nouns that end in "-chen" or "-lein" (endings for diminutive, though this is not always obvious (for example "das Mädchen" is a diminutive of "die Maid")) are neuter. Or nouns that end in "-e" are feminine. Or nouns that end in "-er" are masculine (at least if they mean "a person/object doing something" (counterexample: "das Wunder" (the wonder) - but this is not a person/object doing something) - the same holds for verbs ending in "-erin" being female. Or if you turn a verb into a noun ("das Wandern" from "wandern" - to wander) it will be neuter.
Of course there will be enough nouns for which you simply will have to learn the gender, but I don't believe it is that amount of effort (and most other languages have a much more regular pronounciation than English).
Overall, the intrinsic qualities of a language matter little if at all in driving its adoption.
People learn English because they want to speak with Americans (and earlier the British). Everything else is irrelevant.
This leads to most English being spoken in the country having no native participant. Having too idiomatic English will probably lead to harder communication.
> I rather think most people learn a particular set of language because they have to pick it in school.
You are using "learn" in a completely different sense than rvense is. Far and away the majority of people who have to take language classes in school don't learn anything. People who study a language because they want to communicate with people who speak that language, do learn.
I know few people who really try to learn a new language after school (which is IMHO a pity, since there exist free options in the internet), so for the typical person it is "one either learned the language in school and got to an at least medium level (on which one can, if one wants to (say, because one wants to communicate with others), build later on in life) or one will never learn the language".
There is also the way these things are taught. The most common third language to learn here is German, and instead of, you know, focusing on fluency and learning to actually use the language, or watching good German films or reading interesting German literature, what you get is rote memorization of inflections.
Depends on what you consider as free.
For example German (more inflected than English) has a rather free order of clauses (where the order tells about the emphasis the speaker wants to express) opposed to English.
On the other hand, in English words are often used in a more flexible way than in German (even if you use a similar construction in both languages), because the stricter grammar makes this less comfortable in German than in English. For example: "iron" (en) is "Bügeleisen" (de). In English one can use the verb "to iron" for using the iron while in German there is an own verb "bügeln" for this. Just using the same word for an object and something you do with it is already interfered by the German grammar, in which verbs have to end in "en" or at least "n".
We humans all have the same hardware processing language. If some spoken languages were _actually_ more complex or too complex for that hardware to process, they wouldn't be spoken.
Now, I personaly think that if French actually reached a point where it would be shared as common language by billions of people it would have been broken down to a more efficient form. Creoles and other dialects derived from french all seem to get rid of the redundant bits.
"Irregular" means that a perticular word does not obey the usual rules for inflection (an example of such a rule verb (without to) + "ed" -> simple past, e.g. "jump" -> "jumped"). For example "go" -> "went", "sing" -> "sang". You will usually simply have to learn those.
This isn't true.
However its words have genders to remember to make plurals and match adjectives and possessives. Verbs have desinences for each tense and person. English can be irregular, but Italian has more details to memorize. Still, as you wrote, people don't use the easiest language but the language that gives the most benefits. Latin is so much more difficult than Italian but it had its (very long) heyday, right?