An easy-to-learn writing system is a massive help when learning a language, but the writing system isn't part of the "language" as linguists understand the term. Just a representation of it.
So I totally believe that it's easier to learn English than Mandarin (and maybe easier to learn Spanish than English) because the writing system gives you more hints, but that doesn't have anything to do with the (spoken) language, strictly speaking.
On another note, it's not clear to me that "as phonetic as possible" makes a (written) language easier to read, since our brains process words/morphemes as chunks, rather than sounding them out letter-by-letter (this is how reading Chinese is even possible). So semantic vs. phonetic writing should be thought of as a tradeoff. As an easy example: spaces between words are not phonetically justifiable (there is no pause between words in natural speech), but they sure help reading comprehension a lot.
I totally believe that it's easier to learn English than
Mandarin (and maybe easier to learn Spanish than English)
because the writing system gives you more hints, but that
doesn't have anything to do with the (spoken) language,
strictly speaking.
Sorry, I wasn't actually trying to bring up the writing system at all! I put both English and Mandarin in the "harder" category, even though English's writing system is simpler (though still not as simple as many).
So I totally believe that it's easier to learn English than Mandarin (and maybe easier to learn Spanish than English) because the writing system gives you more hints, but that doesn't have anything to do with the (spoken) language, strictly speaking.
On another note, it's not clear to me that "as phonetic as possible" makes a (written) language easier to read, since our brains process words/morphemes as chunks, rather than sounding them out letter-by-letter (this is how reading Chinese is even possible). So semantic vs. phonetic writing should be thought of as a tradeoff. As an easy example: spaces between words are not phonetically justifiable (there is no pause between words in natural speech), but they sure help reading comprehension a lot.