I studied Russian for three years in high school. By the time I had done that, I could kind of patch together a shaky Russian sentence. I really enjoyed Russian, but I spent all my time memorizing declensions and all that grammar.
After high school I studied Viet Namese, and then Mandarin Chinese. What a joy! A noun is a noun is a noun, you don’t have to change it, you don’t have to do anything to verbs, just find the right places for the words and there you go! I didn’t take my VN studies very far, but within six months I was confident in everyday chitchat conversations. (Of course the situation was different. In high school, I learned Russian from textbooks, even though we had an excellent teacher, Richard the Red, Mr Slater. I learned VN in VN, listening, asking, imitating.)
I made a concentrated effort to learn Mandarin. Within three or four months, I could pretty well understand conversations I heard around me on buses and in restaurants, and I could pretty well converse on most topics. I just had to learn the words and where to put them, it was so much easier than Russian! By the time I had studied Chinese for two years, I was confident reading Classical texts two thousand years old.
But hands down, the hardest language by far is my quirky, irrational native language, English.
Work, worked, worked; walk, walked, walked; like, liked, liked; admire, admired, admired, so far so good, be was been; see saw seen; think thought thought; buy bought bought, drink drank drunk, okay, let’s leave verbs alone for a moment.
Let’s try some adjectives! Yellow, yellower, yellowest; new newer newest; far further/farther furthest / farthest; good better best; bad worse worst. ‘
Oh no, let’s try some nouns! 1 pencil 2 pencils; 1 dog 2 dogs; 1 cat 2 cats; 1 goose 2 geese; 1 deer 2 deer; 1 child 2 children.
Nuts, let’s go back to verbs. She put the phone down. You could say, She put down the phone, and you could say she put it down, but you can’t say *she put down it*. The doctor looked over the report, you could say the doctor looked the report over, or the doctor looked it over, but if you say the doctor looked over it, that means something entirely different.
Oh, I just mentioned the simple verb walk, but somebody could stroll, saunter, pace, amble, stride, tramp, stomp, lumber, slog, shuffle, tread, tramp, traipse, strut, or trudge, so if you study English, you are faced with the world’s largest vocabulary.
So you see why I say that English is by far the most difficult language in the world. I’m lucky it’s my native language so I didn’t have to approach it from afar!