In / On

[jack]

Are these correct? What do they mean?
1. Let’s put some songs in this CD. (When you burn a CD, the songs are in the cd? So when you say it, do you say 'Let's put some songs in this CD or 'Let's put some songs on this CD? Why?
2. Let’s put some songs on this CD.

[Casiopea]

Originally Posted by jack

Are these correct? What do they mean?
1. Let’s put some songs in this CD. (When you burn a CD, the songs are in the cd? So when you say it, do you say 'Let's put some songs in this CD or 'Let's put some songs on this CD? Why?
2. Let’s put some songs on this CD.

in the CD (refers to the list of songs i.e., in the list of songs)
on the CD (refers to the CD i.e., record the song on the CD, Cf. on tape)

[Steven D]

Originally Posted by jack

Are these correct? What do they mean?
1. Let’s put some songs in this CD. (When you burn a CD, the songs are in the cd? So when you say it, do you say 'Let's put some songs in this CD or 'Let's put some songs on this CD? Why?
2. Let’s put some songs on this CD.

To me, songs are always "on a CD".

Good discussion

[jack]

Thanks.
Are these correct? What do these mean?
1. 500hp on a truck. (I think this is right, but I'm not sure why you can't use #2 as well.)
2. 500hp in a truck.

[Casiopea]

Originally Posted by jack

Thanks.
Are these correct? What do these mean?
1. 500hp on a truck. (I think this is right, but I'm not sure why you can't use #2 as well.)
2. 500hp in a truck.

I believe it's due to the fact that h.p. (horse power) is registered on a dial. As for 'in a truck', it sounds fine to my ears. I've heard it used in reference to inside the truck, (i.e., the engine).

[jack]

Thanks.

What do these mean?
1. It is in this aisle.
2. It is on this aisle.

3. I don't want to go outside and get soaked in the rain. (If this is correct, how come? How can you get soaked 'in' the rain?)
4. I don't want to go outside and get soaked on the rain. (If this is incorrect, why?)
5. I don't want to go outside and get soaked by the rain.

6. I don't want to go outside and get soaked in (the) rain. ('the' is specific here right? I have to use it?)

Originally Posted by jack

Thanks.

What do these mean?
1. It is in this aisle. - in the aisle...shopping store aisle.
2. It is on this aisle.

3. I don't want to go outside and get soaked in the rain. (If this is correct, how come? How can you get soaked 'in' the rain?)
4. I don't want to go outside and get soaked on the rain. (If this is incorrect, why?)
5. I don't want to go outside and get soaked by the rain.

6. I don't want to go outside and get soaked in (the) rain. ('the' is specific here right? I have to use it?)

I think both in the rain & by the rain sound fine to me.

[Casiopea]

I agree with Natalie.

As for your other questions:

Originally Posted by jack

1. It is in this aisle.
2. It is on this aisle.

1. means, He is sitting inside this aisle.
2. means, He is sitting on this aisle.

Originally Posted by jack

3. How can you get soaked 'in' the rain?

The rain encompasses you, so you are in(side) the rain.

Originally Posted by jack

4. get soaked on the rain.

4. is incorrect. 'on' means, on top of. The rain is on you, falling on you; you are not falling on top of the rain.

Originally Posted by jack

5. get soaked by the rain.

'by' expresses the means or the tool.

Originally Posted by jack

6. (the) rain. ('the' is specific here right? I have to use it?)

get soaked in rain (medium = liquid e.g., paint)
get soaked in the rain (a thing e.g., the sun, the wind, ect.)

[jack]

1. It is in this aisle.
2. It is on this aisle.

1. means, He is sitting inside this aisle.
2. means, He is sitting on this aisle.

Thanks. This was useful.

Are these correct?
1. Thanks. This was useful.
2. Thanks, this was useful. (If this is correct, does it matter if I use #1 or #2?)
3. Thanks this was useful.