I got a lot of bruises on my legs. I got a lot of bruises on my legs.

I got a lot of bruises on my legs. I got a lot of bruises on my legs.

Sentence is mostly correct, but you can add introductory context information to your sentence to help it sound less stiff. Example: "While on the trip, I got a lot of bruises on my legs."

I don't know when and whyor how. I don't know when or how.

I don't know when and whyhow. I don't know when and how.

It's more common to question "how" you got bruises, instead of "why".

In nNormal lifely, you instantly realize and know after you hit your body because you feel like "Oh〜 iwhen your body has been hit because you think "Oh! That hurt." or "It's really painful." Normally, you instantly realize when your body has been hit because you think "Oh! That hurt" or "It's really painful."

In normaldaily life, you instantly realize and know after you hit your body because you feel like "Oh〜 iw! That hurt." or "It's really painful." In daily life, you instantly realize and know after you hit your body because you feel like "Ow! That hurt." or "It's really painful."

Howebver, I did not. However, I did not.

Howebver, I did not. However, I did not.

Maybe my attention were not in that way and I wasI was distracted and lost in conversation with my friends. Maybe I was distracted and lost in conversation with my friends.

Maybe my attention were not in that way andas on something else or I was lost in conversation with my friends. Maybe my attention was on something else or I was lost in conversation with my friends.

I didmade a campfire twice. I made a campfire twice.

I didsat by the campfire twice. I sat by the campfire twice.

I ate burntoasted marshmallows. I ate toasted marshmallows.

I ate burnroasted marshmallows. I ate roasted marshmallows.

"Burned" would indicate that they where very charred and inedible.

Some poeple wereople burned their marshmallows untill it turned to the black on purpose. Some people burned their marshmallows until it turned black on purpose.

Some poeople were burnedroasting theirs untill it turned to the black on purpose. Some people were roasting theirs until it turned black on purpose.

I thoughink that there are some people who do the same thingat in every country, not only Japan. I think that there are some people who do that in every country, not only Japan.

I thought there are some people who do the same thing in every country, not only Japan. I thought there are some people who do the same thing in every country, not only Japan.

This is very true.

AtDuring the second campfire, we tried to make a fire to eat marshmallows bywith a group with instructors. During the second campfire, we tried to make a fire to eat marshmallows with a group with instructors.

At the second campfire, wea group of us with our instructors tried to make a fire to eat marshmallows by a group with instructorsagain. At the second campfire, a group of us with our instructors tried to make a fire to eat marshmallows again.

I couldn't even haveget a big spark. I couldn't even get a big spark.

But I couldn't even have a bigcreate a big enough spark. But I couldn't create a big enough spark.

One person wereas like a professional and he easoily made a fire. One person was like a professional and easily made a fire.

One person wereseemed like a professional and he easoily made a fire. One person seemed like a professional and he easily made a fire.

I also didwent hiking for five hours. I also went hiking for five hours.

I also did hikinghiked for five hours. I also hiked for five hours.

Here is another sentence where you could add context to which day you did the hiking. Example: "Sitting by the fire, I realized how tired I was because I also hiked for five hours earlier that day."

We were fine untill the second break, but we were getting tired and, so some group peoplemembers couldn't chat anymore. We were fine until the second break, but we were getting tired, so some group members couldn't chat anymore.

We were fine untill the second break, but we were getting tired and some group people couldn't chat barely talk. We were fine until the second break, but we were getting tired and some group people could barely talk.

Good phrases for this situation: > People had to 'catch their breath'. > People were 'out of breath'.

it hadThere were some steep hills. There were some steep hills.

itThe hike had some steep hills. The hike had some steep hills.

SThe snacks and foods that we got werehad really helpful toed us recover our conditions, energy. Especifically, the chocolate. The snacks and food that we had really helped us recover our energy. Especially the chocolate.

I heard I wouldthat we will jump into mud onduring next year's trip. I heard that we will jump into mud during next year's trip.

IThat soundeds more taought than this trip. That sounds more tough than this trip.

It sounded more taughtstructured than this trip. It sounded more structured than this trip.

This is the only sentence I'm not quite sure what you are trying to say. "Taught" refers more to learning about something. Example: "I was taught not to put my elbows on the table when eating." But it sounds unnatrual for a trip to be "taught".