Prietenului meu îi place grădinăritul.

Because a plăcea uses the dative for the person who experiences the liking.

So:

• prietenul meu = my friend
• prietenului meu = to my friend

In this sentence, Romanian is built more like Gardening is pleasing to my friend, so my friend appears in the dative.

For a masculine singular noun like prieten, the definite dative/genitive form is typically -ului, giving prietenului.

Îi is a short unstressed pronoun meaning to him or to her.

Here it refers back to prietenului meu. Romanian very often uses this kind of clitic doubling, where you have:

• the full phrase: prietenului meu
• and the short pronoun: îi

So Prietenului meu îi place... literally has both to my friend and to him.

From an English point of view, it feels redundant, but in Romanian it is normal and often expected.

This is called clitic doubling. With a full dative phrase, Romanian commonly also uses the matching short pronoun:

• Prietenului meu îi place grădinăritul.

If you remove the full noun phrase, you can still say:

• Îi place grădinăritul. = He/She likes gardening.

But if you keep prietenului meu, the îi is usually part of the natural standard structure.

Because the verb agrees with the thing that is liked, not with the person who likes it.

Here, grădinăritul is singular, so the verb is singular:

• grădinăritul place → îi place

If the thing liked were plural, you would use plac:

• Prietenului meu îi plac florile. = My friend likes flowers.

Yes. Romanian a plăcea does not work like English to like.

English:

• My friend likes gardening.

Romanian structure:

• To my friend, gardening is pleasing.

So:

• prietenului meu = the person affected, in the dative
• grădinăritul = the grammatical subject
• place = agrees with grădinăritul

That is the key pattern to understand.

Because grădinăritul is the definite form of grădinărit.

• grădinărit = gardening / horticulture, as a noun
• grădinăritul = the gardening

But in Romanian, abstract nouns and general activities often appear in the definite form where English would just say gardening, music, sports, and so on.

Compare:

• Îmi place muzica. = I like music.
• Îi place sportul. = He/She likes sports.
• Îi place grădinăritul. = He/She likes gardening.

So the definite article here does not necessarily mean a specific instance of gardening.

No. It is a noun.

It means gardening as an activity or field. In this sentence, it functions as the subject of the verb place.

So grammatically, Romanian is saying that gardening is what pleases your friend.

Because Romanian possessive adjectives usually come after the noun in normal usage.

So:

• prietenul meu = my friend
• cartea mea = my book

In this sentence, the noun is in the dative:

• prietenului meu = to my friend

So the position of meu is completely normal.

In standard Romanian, that sounds unnatural or incorrect.

With a full dative phrase like prietenului meu, Romanian normally also uses the clitic:

• Prietenului meu îi place grădinăritul.

If you want to omit something, you would usually omit the full noun phrase, not the clitic:

• Îi place grădinăritul.

So for learners, the safest rule is: if you say the full dative noun phrase, keep îi too.

Yes, Romanian word order is somewhat flexible, but not every rearrangement is equally natural.

The given sentence is very natural:

• Prietenului meu îi place grădinăritul.

You can also hear:

• Îi place grădinăritul prietenului meu is not a good substitute, because it may sound like my friend's gardening, as if prietenului meu belongs with grădinăritul.

So for this meaning, the safest and clearest order is the original one:

• Prietenului meu îi place grădinăritul.

Îi is pronounced very quickly, usually as one compact sound, roughly like uhy or iy said fast, depending on accent and speech speed.

In normal speech:

• îi place flows together smoothly

The important thing for learners is:

• it is short
• it is unstressed
• it attaches closely to the verb

Then the verb would become plac instead of place, because it would agree with a plural subject.

For example:

• Prietenului meu îi plac florile. = My friend likes flowers.
• Prietenului meu îi plac legumele. = My friend likes vegetables.

So:

• singular thing liked → îi place
• plural things liked → îi plac