Tu idea me parece interesante.

Because me means to me, and the verb parecer works like to seem.

So the structure is:

• Tu idea = the subject
• me = to me
• parece = seems
• interesante = interesting

Literally, the sentence is something like Your idea seems interesting to me.

You do not use yo here because yo is a subject pronoun, and I is not the subject of this sentence. The subject is tu idea.

In this sentence, parecer means to seem or to appear.

So:

• Tu idea me parece interesante = Your idea seems interesting to me

In everyday English, we often translate this more naturally as I think your idea is interesting, but grammatically Spanish is using seem, not think.

That is an important difference:

• Me parece interesante = It seems interesting to me
• Pienso que es interesante = I think it is interesting

The first can sound a little softer or less direct.

Because the verb agrees with tu idea, which is third person singular.

The subject is tu idea, so the verb must be parece:

• yo parezco = I seem
• tú pareces = you seem
• tu idea parece = your idea seems

So parece is used because idea is she/it grammatically, and singular.

Because tu here is a possessive adjective meaning your.

Spanish distinguishes:

• tu = your
• tú = you

So in Tu idea, the word means your, so it has no accent.

Examples:

• Tu idea = your idea
• Tú tienes una idea = you have an idea

Because interesante is an adjective with the same form for masculine and feminine singular.

So you get:

• un libro interesante
• una idea interesante

The adjective only changes in the plural:

• un libro interesante
• unos libros interesantes
• una idea interesante
• unas ideas interesantes

So the feminine noun idea does not force a different singular form here.

Yes.

• Tu idea parece interesante = Your idea seems interesting
• Tu idea me parece interesante = Your idea seems interesting to me

The version with me makes it clear that this is your personal impression/opinion. Without me, the sentence sounds a bit more general or neutral.

Both are correct.

Es interesante is stronger and more direct:

• Tu idea es interesante = Your idea is interesting
• Tu idea me parece interesante = Your idea seems interesting to me

With parece, the speaker is presenting it as an impression or opinion. It can sound slightly softer, more polite, or less absolute.

So if you want to sound less blunt, me parece interesante is very useful.

Yes, absolutely.

That means:

• I think your idea is interesting

Compared with Tu idea me parece interesante:

• Pienso que... is a more explicit statement of thought
• Me parece... often sounds a bit more natural, conversational, and softer in many contexts

Both are common, but me parece is especially useful when giving opinions politely.

Because Spanish usually does not use an article before a noun when there is a possessive adjective like mi, tu, su, nuestro.

So:

• tu idea = your idea
• not la tu idea

This is different from English in some other structures, but in standard Spanish, the possessive already does the job.

Yes, but the basic order here is the most neutral one:

• Tu idea me parece interesante

You may also hear:

• Me parece interesante tu idea

That version is also correct, but it shifts the focus a bit toward interesante or the speaker’s reaction first.

For a learner, the original order is the easiest and most standard to use.

In standard Peninsular Spanish, it would sound approximately like:

too ee-DE-a meh pah-RE-theh een-teh-reh-SAN-teh

A few useful notes:

• idea has three syllables: i-de-a
• parece has the stress on re: pa-RE-ce
• In much of Spain, the c before e in parece is pronounced like the th in think
• interesante has the stress on san: in-te-re-SAN-te

So in Spain, parece is typically pronounced pa-RE-the.