I’ve hadve many business trips these days, so sometimes I can’t do my routine English study, and that makes me depressed. I have many business trips these days, so sometimes I can’t do my routine English study, and that makes me depressed.

“These days” implies present tense, if you did mean that the business trips are over, then “recently” is better.

I’ve had many business trips these days/ recently, so sometimes I can’t do my routine English study sessions, and that makes me depressed. I’ve had many business trips these days/ recently, so sometimes I can’t do my routine English study sessions, and that makes me depressed.

i saw another edit that edited "I've had" but it seeeeeems fine here I think. Another word you could use is recently. Routine can be used as an adjective too! Just with some changes as above. You can also say "I can't do my usual English studying routine", routine is a noun here!

I hope to work inat the same time every day, and have ample private time. I hope to work at the same time every day, and have ample private time.

I hopwould like to work in the same timehours every day, and have ample private time. I would like to work the same hours every day and have ample private time.

I think this is what you mean? If you are wishing for a different schedule, then I suggest "would like to" expresses this better than "hope." "Hope" is usually for an actual situation: "I hope you get better soon." "I hope you like your new job." "I hope he will get here early." "I hope she doesn't fail the exam again." It is more hypothetical to say "would like to." We understand that it might not happen.

I hope to work inat the same time/ for the same duration every day, andso that have ample private time. I hope to work at the same time/ for the same duration every day, so that have ample private time.

so that adds connectivity to the previous sentence, that it relates, there is cause and effect.

I wonder that do employees of a trading companycorporate jobs in your country need to drink a lot of alcohol and make noise at a drinking(go to / be visible at) partyies? I wonder that do employees of corporate jobs in your country need to drink a lot of alcohol and (go to / be visible at) parties?

“Trading company” makes people think of shipping businesses, finance companies or wholesalers. Even though dictionaries will list trading company as the translation of 商社, I think that’s a pretty unnatural way in English to refer to a company unless you’re contrasting with closed down companies or writing an academic report. Corporate as an adjective or just plain “company” as a noun are much more natural. “Make noise at” is pretty unnatural in English. If you’re just talking about being at the party “go to parties” is more natural, while if you want to point out a need to stand out/make your presence known, then “be visible at” is better. I think in Japan 飲み会 is considered more separate to パーティー but in English we don’t really specify the difference. Unless it’s a kid’s party or like a community event that involves kids, it’s assumed the default is that alcohol will be present.

I wonder that, do employees of a trading companycorporations in your country need to drink a lot of alcohol and make noise at aattend noisy drinking partyies? I wonder, do employees of corporations in your country need to drink a lot of alcohol and attend noisy drinking parties?

I am guessing at your meaning. I borrowed "corporation" from @araigoshi's corrections.

I wonder that doif employees of a trading company in your country need to drink a lot of alcohol and make noise at a drinking party? I wonder if employees of a trading company in your country need to drink a lot of alcohol and make noise at a drinking party?

small grammar edit, not "that"