Αυτό το κίτρινο πουκάμισο είναι ωραίο, αλλά θέλω κάτι που να ταιριάζει καλύτερα με το μπλε σακάκι μου.

Yes, αυτό means this, but in Greek it is very normal to use the demonstrative together with the definite article:

• αυτό το πουκάμισο = this shirt
• literally: this the shirt

This structure is standard Greek. English does not do this, but Greek usually does.

The words agree with the noun:

• αυτό = neuter singular demonstrative
• το = neuter singular article
• πουκάμισο = neuter singular noun

So Αυτό το κίτρινο πουκάμισο is the natural way to say this yellow shirt.

Because πουκάμισο is a neuter singular noun, and the words connected to it must agree with it.

Here is the agreement:

• αυτό = neuter singular
• το = neuter singular article
• κίτρινο = neuter singular adjective
• πουκάμισο = neuter singular noun
• ωραίο = neuter singular adjective

Greek adjectives and demonstratives change form depending on:

• gender
• number
• case

For example:

• αυτό το κίτρινο πουκάμισο = this yellow shirt
• αυτή η κίτρινη μπλούζα = this yellow blouse
• αυτό το κίτρινο σακάκι = this yellow jacket

So the -ο ending here is mainly because the noun is neuter singular.

Ωραίος / ωραία / ωραίο is a very common adjective meaning things like:

• nice
• lovely
• good-looking
• beautiful
• pleasant

The exact English translation depends on context.

In Αυτό το κίτρινο πουκάμισο είναι ωραίο, ωραίο most naturally means something like:

• This yellow shirt is nice
• This yellow shirt looks good

It is a very common, everyday word in Greek, and often broader than any single English word.

Because ωραίο here is not directly attached to the noun inside the noun phrase. It is a predicate adjective, used after the verb είναι:

• Το πουκάμισο είναι ωραίο = The shirt is nice

Compare:

• το ωραίο πουκάμισο = the nice shirt
  
  • adjective directly modifies the noun
• το πουκάμισο είναι ωραίο = the shirt is nice
  
  • adjective comes after είναι

This works very much like English:

• the nice shirt
• the shirt is nice

Κάτι means something.

So:

• θέλω κάτι = I want something

It is very common in Greek for speaking about an unspecified thing.

In this sentence, the speaker does not say exactly what item they want. They just want something that matches better.

Also, κάτι is neuter, which is common for indefinite words referring to an unspecified thing.

This is one of the most important grammar points in the sentence.

Greek often uses που να + subjunctive when talking about something wanted, sought, expected, or not yet identified.

So:

• θέλω κάτι που να ταιριάζει...
  = I want something that matches...

This suggests:

• the thing is not identified yet
• the speaker is looking for such a thing
• it is about a desired characteristic

If you said κάτι που ταιριάζει, it can sound more like:

• something that does match
• a more factual or descriptive statement

With θέλω, Greek very naturally prefers που να ταιριάζει in this kind of sentence.

A useful way to remember it:

• που + indicative = more factual / descriptive
• που να + subjunctive = wanted / possible / sought-after

Yes. After να, Greek uses the subjunctive-type verb form.

In Modern Greek, the subjunctive is usually expressed with:

• να
  • verb

So:

• να ταιριάζει = to match / that it match

In this sentence:

• που να ταιριάζει καλύτερα... means
• that matches better...
• or more literally, that may/should match better...

You do not need a special verb ending that looks very different here; the important signal is να.

Because καλύτερα here is an adverb, not an adjective.

It modifies the verb ταιριάζει:

• ταιριάζει καλύτερα = matches better

Compare:

• καλύτερο πουκάμισο = a better shirt
  
  • adjective, describing a noun
• ταιριάζει καλύτερα = matches better
  
  • adverb, describing how the matching happens

So here Greek uses the adverb form because the meaning is about matching more well / better, not about a better item in itself.

Ταιριάζω means things like:

• to match
• to suit
• to go well with
• to fit well together

It is very often used for:

• clothes
• colors
• styles
• people or personalities
• situations

In this sentence:

• να ταιριάζει καλύτερα με το μπλε σακάκι μου means
• to match better with my blue jacket

So yes, it is very common with clothes, but not limited to clothes.

Examples:

• Αυτό το χρώμα σου ταιριάζει. = This color suits you.
• Τα παπούτσια ταιριάζουν με την τσάντα. = The shoes match the bag.

Because ταιριάζω commonly takes με when you say what something matches with.

So:

• ταιριάζει με το σακάκι = it matches with the jacket

This is just the normal preposition used with this meaning.

You can think of it as:

• to go with
• to match with

So the structure is:

• κάτι που να ταιριάζει καλύτερα με το μπλε σακάκι μου
• something that matches better with my blue jacket

Good question. Μπλε is usually indeclinable, which means it often does not change form for gender, number, or case.

So you can get:

• το μπλε σακάκι
• η μπλε μπλούζα
• ο μπλε τοίχος (though some speakers may use other patterns in some contexts)

By contrast, κίτρινος / κίτρινη / κίτρινο is a regularly declining adjective, so it changes form.

So:

• κίτρινο πουκάμισο changes because κίτρινος declines
• μπλε σακάκι stays μπλε because μπλε usually does not decline

In Greek, possessive pronouns like μου, σου, του, της, μας, σας, τους usually come after the noun.

So:

• το σακάκι μου = my jacket
• literally: the jacket my

This is the normal Greek pattern.

Compare:

• my jacket in English
• το σακάκι μου in Greek

Notice also that Greek usually keeps the article:

• το σακάκι μου not just
• σακάκι μου in a neutral standard sentence

Because Greek normally uses the definite article with possessed nouns:

• το σακάκι μου = my jacket
• literally: the jacket my

This is standard Greek grammar. English and Greek simply work differently here.

So:

• English: my blue jacket
• Greek: το μπλε σακάκι μου

The article is not extra emphasis; it is just the usual structure.

Both can work, depending on tone and context.

Literally:

• θέλω = I want

But in everyday situations like shopping, θέλω can often sound natural in English as:

• I’d like

So the sentence could be understood as either:

• This yellow shirt is nice, but I want something that matches my blue jacket better
• This yellow shirt is nice, but I’d like something that goes better with my blue jacket

The Greek itself is not unusually rude; context matters.

Yes, it sounds very natural.

It has several very typical features of everyday spoken and written Greek:

• Αυτό το... for this...
• είναι ωραίο for is nice
• θέλω κάτι... for I want something...
• που να ταιριάζει... for a desired quality
• με το ... μου for with my ...

A Greek speaker could naturally say this in:

• a clothes shop
• a conversation with a friend
• a discussion about what to wear

So this is a very useful real-life sentence to learn from.