На березі моря я дивлюся на хвилі.

Because на can take different cases depending on the meaning.

• на березі = on/at the shore in the sense of location → locative case
• на берег = onto the shore in the sense of movement toward a place → accusative case

So in this sentence, the speaker is already there, not moving there, so беріг becomes березі.

• dictionary form: беріг = shore
• locative singular: на березі = on/at the shore

Here моря is in the genitive singular because it means of the sea.

So:

• берег моря = the shore of the sea
• на березі моря = on the shore of the sea

This is a very common Ukrainian pattern:

• дах будинку = the roof of the house
• сторінка книги = the page of the book
• берег моря = the shore of the sea

So моря depends on беріг, not on на.

Because the verb дивитися normally takes на + accusative when it means to look at something.

So:

• дивитися на море = to look at the sea
• дивитися на людей = to look at people
• дивитися на хвилі = to look at the waves

This is just the standard pattern of the verb. English uses look at, and Ukrainian uses дивитися на.

Хвилі here is accusative plural of хвиля (wave).

Because дивитися на takes the accusative, the object must be in that case.

Singular:

• хвиля = wave
• дивлюся на хвилю = I look at the wave

Plural:

• хвилі = waves
• дивлюся на хвилі = I look at the waves

A useful detail: for inanimate plural nouns, the accusative plural is usually the same as the nominative plural, so хвилі looks the same in both cases.

Дивлюся is the 1st person singular present tense of дивитися:

• дивитися = to look, to watch
• я дивлюся = I look / I am looking

The -ся is part of the verb. In many verbs, it gives a reflexive or middle meaning, but you should usually learn дивитися as a complete dictionary form.

Conjugation:

• я дивлюся = I look
• ти дивишся = you look
• він / вона дивиться = he/she looks
• ми дивимося = we look
• ви дивитеся = you look
• вони дивляться = they look

Yes, it can be omitted.

Ukrainian often leaves out subject pronouns when they are clear from the verb ending. Since дивлюся already means I am looking, я is not strictly necessary.

So both are possible:

• На березі моря я дивлюся на хвилі.
• На березі моря дивлюся на хвилі.

Including я can add a little emphasis or simply make the sentence sound more explicit.

Ukrainian word order is flexible. The sentence begins with На березі моря to set the scene first: On the shore of the sea...

So this version feels natural:

• На березі моря я дивлюся на хвилі.

But other orders are also possible:

• Я дивлюся на хвилі на березі моря.
• Я на березі моря дивлюся на хвилі.

The basic meaning stays similar, but the emphasis changes. Starting with the place often sounds descriptive or narrative.

It can mean both.

Ukrainian present tense usually covers both the English simple present and present continuous, depending on context.

So я дивлюся на хвилі can mean:

• I look at the waves
• I am looking at the waves

In this sentence, because it describes a scene happening now, English often translates it as I am looking at the waves.

These are different ideas:

• дивитися = to look (at), to watch

  • active action
  • Я дивлюся на хвилі. = I am looking at the waves.

• бачити = to see

  • perception, not necessarily intentional
  • Я бачу хвилі. = I see the waves.

• подивитися = to take a look, to look for a moment

  • usually perfective
  • Я подивлюся на хвилі. = I will take a look at the waves.

So in your sentence, дивлюся is used because the speaker is actively looking.

Because Ukrainian has no articles like a/an/the.

Whether something is the sea, a sea, the waves, or just waves is understood from context.

So:

• море can mean sea or the sea
• хвилі can mean waves or the waves

In this sentence, English naturally uses the because the setting is specific:

• the shore of the sea
• the waves

In this sentence, березі is the locative singular of беріг (shore, bank).

But you may also see similar-looking forms from other nouns, so it is important to learn the dictionary form together with the sentence.

For this noun:

• беріг = shore/bank
• на березі = on the shore / on the bank

Also note that беріг can mean either:

• the shore of a sea, lake, or river
• the bank of a river

So на березі моря specifically tells you it is the seashore.

Yes, but the meaning changes slightly.

• на березі моря = on the shore of the sea, right at the shore
• біля моря = near the sea, more general

So if you want the precise image of standing on the shore, на березі моря is better. If you just mean somewhere close to the sea, біля моря works.

In careful pronunciation, дивлюся is roughly pronounced like dyv-LYU-sya.

A few useful points:

• the stress is on лю: дивлЮся
• я after с gives a sya-like sound
• in normal speech, -ся can sound a bit lighter or shorter than English speakers expect

The important thing for learners is:

• pronounce the лю clearly
• keep -ся attached to the verb as one word

So think of it as one unit: дивлюся.