1. That sounds fun to me.

(What is the part of sppech of 'fun'? Is it a noun or an adjective? What about "funny" instead of "fun"?

2. That sounds funny to me.
3. That sounds interesting to me.

(Do the three have the same meaning?)

The word "fun" is essentially a noun, but in informal English is also used as an adjective:

http://www.answers.com/fun

The three sentences don't have the same meening.

#1 -- something enjoyable

#2 -- something to make you laugh

#3 -- something to keep your attention

Sorry -- meaning (not "meening"!!)

1. In the sentence "That sounds fun to me," the word "fun" is used as a noun. It refers to a source of enjoyment or amusement. It is not being used to describe something, so it is not being used as an adjective. However, if you were to use the word "funny" instead of "fun," it would be an adjective. "Funny" describes something that causes laughter or amusement.

2. When you say "That sounds funny to me," the word "funny" is used as an adjective. It describes something that is amusing or comedic, causing laughter or amusement.

3. The three sentences, "That sounds fun to me," "That sounds funny to me," and "That sounds interesting to me," do not have exactly the same meaning. However, they all convey a sense of personal enjoyment or positive reaction.

- "That sounds fun to me" implies that the speaker finds something enjoyable or entertaining.
- "That sounds funny to me" suggests that the speaker finds something amusing or comical.
- "That sounds interesting to me" implies that the speaker finds something intriguing or engaging, sparking curiosity or fascination.

While there may be some overlap in meaning, each sentence conveys a slightly different nuance depending on the specific word used.