A more natural sentence to my ear would be "would you like to try an experiment?". The second sentence sounds a bit formal to me and I haven't heard anyone say this before. I'm also American, so maybe this is said more frequently in British English. :)

I think what you are asking is, what do you say if you are the doctor meeting a patient for the first time? I usually hear things like this: "Hey, how are you feeling? What brings you in today?" If you say "what's wrong with you", this is very brash. I wouldn't say this at the doctor. In your second option, "I have a sore throat" is ok, but "what about you" doesn't make sense here.

Hey Kimura, to be clear, "vigilante" and "vigilant" are different words. "Vigilante" (noun) is a person who illegally enforces the law according to their own perception. "Vigilant" (adjective) describes someone who watches for danger. A police officer is vigilant because he/she watches carefully for danger in order to protect citizens. Regarding this sentence, "watchful" would loosely translate to "carefully paying attention to something", in this case, the alignment of shared values. Please let me know if I need to clarify anything!

You're really close. In American English, I would say: "Today we are talking about the pronunciation of 10 brands that have Brazilian names, but are pronounced differently in English". We mostly use the word "exist" to talk about things that live/occur in one place. A brand would not "exist" in Brazil, it would be "a Brazilian brand", or be "a brand from Brazil". Example: There is a bird that exists only in Brazil. (There is a bird that is not found anywhere else in the world, only in Brazil).

You're really close. In American English, I would say: "Today we are talking about the pronunciation of 10 brands that have Brazilian names, but are pronounced differently in English". We mostly use the word "exist" to talk about things that live/occur in one place. A brand would not "exist" in Brazil, it would be "a Brazilian brand", or be "a brand from Brazil". Example: There is a bird that exists only in Brazil. (There is a bird that is not found anywhere else in the world, only in Brazil).

"I'm busy right now." ---> This is 100% correct. "Get someone else to deal with it." --> This sounds rude, I would not say this unless I was frustrated. "Find somebody else to deal with it." --> This is 95% correct. I would say "Find SOMEONE else to HANDLE it." Also, a warning, this sentence also sounds slightly rude. If you wanted to be more polite, you could say: "I would find someone else to handle this." This sounds more polite and native English speakers won't accidentally mistake your tone as rude. :) "Deal with it" is usually used on its own as a sentence. Think of this as a fixed phrase, maybe something you would say to stop an argument. "I don't want to go to school, I'm really tired today." "Deal with it, you don't have a choice. School is expensive." Another note - this is also slightly rude/curt. It's best to use this with friends/family who won't mistake your tone.

The difference here is in how the action is perceived. In my head, someone who is "fixated" on something is very focused, but in a healthy way. Another good word here would be 'driven' or 'dedicated'; all of these words generally have a positive connotation. Obsessed individuals compulsively think about something and can't help this, so this is considered 'unhealthy' and has a negative connotation. Example: Chris is very fixated on becoming a doctor. He's wanted to be a doctor since he was a kid. Chris is obsessed with cars. He only wants to talk about them whenever we go out for food.