For a long time, maybe for a few years, I had been thinking someone nearby was vacuum-cleaning in the morning, in the afternoon, and in the evening, almost everyday until one day this idea suddenly came to me that it might have been the sound of electric cars. For a long time, maybe for a few years, I had been thinking someone nearby was vacuum-cleaning in the morning, in the afternoon, and in the evening, almost everyday until one day this idea suddenly came to me that it might have been the sound of electric cars.

The comma after "evening" is the "Oxford comma" and depending on who you ask, it's optional or mandatory. I think after a list, a comma is a good idea.

For a long time, maybe for a few years, I had been thinking someone nearby was vacuum-cleaning in the morning, (in the) afternoon, and (in the evening) almost every day until one day thise idea suddenly came to me that it might have been the sound of electric cars. For a long time, maybe for a few years, I had been thinking someone nearby was vacuuming in the morning, (in the) afternoon, and (in the evening) almost every day until one day the idea suddenly came to me that it might have been the sound of electric cars.

I am in the U.S. I am in the U.S.

I’m currently living in the US.

I'm still here.

I live in a city that I love so muchgreatly, though today the city is suffering from problems. I live in a city that I love greatly, though today it is suffering from problems.

"In a city that I love so much" sounds like a preposition preparing to discuss life in that city, however the subject of the next sentence is the city itself so this is maybe ungrammatical or at least semantically incorrect.

In a city that I love so much, though today I noticed the city is suffering from problems. In a city that I love so much, though today I noticed the city is suffering from problems.

If you write today I noticed it means that the city has been and continues to suffer from many problems and not only today.

I live in a city that I love so much, though today the city is suffering from problems. I live in a city that I love so much, though today the city is suffering from problems.

元の文は sentence fragment です。

I have always liked the sound that something goes the sky makesof aircrafts as pass by. I have always liked the sound of aircrafts as pass by.

"something goes the sky makes." is unfortunately ungrammatical. Perhaps "things going through the sky make." "Things" instead of "something," because rather than talking about some unidentified object flying overhead, we are talking about a category of things. Now, if it's truly the helicopter, it might be best to declare its existence first, like this: "Something passes by every day (now that we've introduced the reader to it, we can comment on it:) and it produces a sound that I like."

I have always liked the sound that something goesa specific sound I often hear in the sky makes. I have always liked a specific sound I often hear in the sky.

I have always liked the sound thatof something goesin the sky makes. I always liked the sound of something in the sky.

One day, I discovered it was coming from a helicopter. One day, I discovered it was coming from a helicopter.

They make the same or similar sound that I heard in 'Star Wars' in my country when I was a teenager back in my country. They make the same or similar sound that I heard in 'Star Wars' when I was a teenager back in my country.

I wonder if there's a secret rule in English that "when" comes before "in," or if it's just in this context. Just feels better to me this way.

They make the same or similar sound thatas the one I heard in 'Star Wars' in my country when I was a teenager. They make the same or similar sound as the one I heard in 'Star Wars' in my country when I was a teenager.

Same or similar + AS

They make the same or similar sound that I heard in 'Star Wars' when I watched it in my country when I was a teenager. They make the same or similar sound that I heard in 'Star Wars' when I watched it in my country when I was a teenager.

難しい文だと思いますが、よく出来ました。

Therefore the sound, to me, is of adventures that belong to movies. Therefore the sound, to me, is of adventure.

I checked the Japanese version to see what you might've intended by this, but the 結びつく in "映画の中の冒険と結びついている" is pretty hard to translate, at least literally. I went with "is of adventure" because "reminds me of watching those movies" was my first thought, but somehow (whether this is right or wrong) it felt about as close to literal as I could get to the wording in your Japanese version and it's perfectly natural English.

Therefore the sound, to me, is of adventures that belong toin movies. Therefore the sound, to me, is of adventures that belong in movies.

I hear other sounds, too, but, since it'this essay is getting long, maybe I'll talk about them another time. I hear other sounds, too, but, since this essay is getting long, maybe I'll talk about them another time.

I hear other sounds, too, but, since it's getting longate, maybe I'll talk about them another time. I hear other sounds, too, but, since it's getting late, maybe I'll talk about them another time.

I hear other sounds, too, but, since it'my essay is getting long, maybe I'll talk about them another time. I hear other sounds, too, but, since my essay is getting long, maybe I'll talk about them another time.