Με λίγο δυόσμο στο νερό και λίγη ησυχία, νιώθω ότι η μέρα μου γίνεται αμέσως καλύτερη.

Because λίγο and λίγη have to agree with the type of noun they go with.

• δυόσμος is a masculine noun, so in this sentence it appears as λίγο δυόσμο
• ησυχία is a feminine noun, so it becomes λίγη ησυχία

A useful way to think about it is:

• λίγος = masculine
• λίγη = feminine
• λίγο = neuter

However, with mass nouns or quantities, Greek sometimes uses these forms a bit more flexibly than English learners expect. Here, the important thing is that ησυχία clearly takes the feminine form λίγη.

Because it comes after με, and με takes the accusative case in Modern Greek.

So:

• dictionary form: ο δυόσμος
• after με: με δυόσμο

This is very common in Greek:

• ο καφές → με καφέ
• ο φίλος → με τον φίλο
• ο δυόσμος → με λίγο δυόσμο

So δυόσμο is not a different word; it is the accusative form of δυόσμος.

Here με means with.

So:

• με λίγο δυόσμο στο νερό = with a little mint in the water

Greek με is very common and can mean with, whether you are talking about accompaniment, ingredient, method, or manner.

Examples:

• με φίλους = with friends
• με ζάχαρη = with sugar
• με χαρά = with joy

In your sentence, it introduces the things that help create the feeling described afterward.

Because στο is the contracted form of σε + το.

So:

• σε το νερό → στο νερό

This contraction is standard Greek.

Other common contractions:

• σε + την → στη(ν)
• σε + τον → στον
• σε + τα → στα

So στο νερό simply means in the water or into the water, depending on context. Here it means in the water.

There is no missing verb in the sense of bad grammar; Greek often uses this kind of compact structure naturally.

The phrase:

• Με λίγο δυόσμο στο νερό και λίγη ησυχία

works like a prepositional phrase plus a second coordinated element. In natural English, you might expand it mentally as:

• With a little mint in the water and with a little peace and quiet...

Greek often avoids repeating με when it is understood from the first part.

So the full sense is:

• With a little mint in the water and a little quiet, I feel that...

ότι introduces a clause, usually equivalent to that in English.

So:

• νιώθω ότι... = I feel that...

Here the structure is:

• νιώθω = I feel
• ότι η μέρα μου γίνεται αμέσως καλύτερη = that my day immediately becomes better

In English, that is often optional:

• I feel my day becomes better
• I feel that my day becomes better

In Greek, ότι is very common and often clearer.

Because μου here is a weak possessive pronoun, and it normally comes after the noun.

So:

• η μέρα μου = my day
• literally: the day of me

This is a very common Greek pattern:

• το σπίτι μου = my house
• η φίλη μου = my friend
• ο καφές μου = my coffee

Greek often uses the definite article where English uses a possessive alone, so η μέρα μου is the normal way to say my day.

Greek often uses γίνομαι + adjective to mean become + adjective.

So:

• η μέρα μου γίνεται καλύτερη = my day becomes better

This is a very natural Greek way to express change of state.

You could think of it as:

• γίνεται = becomes
• καλύτερη = better

English often prefers a verb like improves, but Greek is perfectly natural with becomes better.

Because καλύτερη agrees with η μέρα, which is a feminine singular noun.

Agreement matters in Greek adjectives.

• η μέρα = feminine singular
• therefore καλύτερη = feminine singular form of better

Compare:

• ο καφές είναι καλύτερος = the coffee is better
• η μέρα είναι καλύτερη = the day is better
• το νερό είναι καλύτερο = the water is better

So the adjective changes form to match the noun.

αμέσως means immediately or right away.

In this sentence:

• γίνεται αμέσως καλύτερη = becomes immediately better = more naturally in English, gets better right away

Greek adverbs like αμέσως are often placed before the adjective or near the verb. The placement here is normal and emphasizes how quickly the improvement happens.

It can mean both silence and peace/quiet, depending on context.

In this sentence, λίγη ησυχία most naturally means:

• a little peace and quiet
• a little quiet

It does not have to mean total silence. It often suggests calm, lack of disturbance, restfulness, or a peaceful atmosphere.

Because Greek word order is flexible, and the speaker is emphasizing the conditions first.

So the sentence starts with:

• Με λίγο δυόσμο στο νερό και λίγη ησυχία...

This sets the scene first, almost like:

• With a little mint in the water and a little peace and quiet, ...

Then comes the main idea:

• νιώθω ότι...

If you changed the order, it would still be understandable, but the original version feels natural and gives special attention to the things that create the pleasant feeling.

The stressed syllables are:

• Με λίγο δυόσμο στο νερό και λίγη ησυχία, νιώθω ότι η μέρα μου γίνεται αμέσως καλύτερη.

A rough guide for stress:

• LÍ-go
• dyÓ-smo
• ne-RÓ
• LÍ-ghi
• i-si-HÍ-a
• NIO-tho
• Ó-ti
• MÉ-ra
• GÍ-ne-te
• a-MÉ-sos
• ka-LÝ-te-ri

A few pronunciation notes:

• δυ in δυόσμο sounds roughly like thyoo or dhyoo, depending on speech and accent habits
• ιώ in νιώθω is pronounced smoothly, roughly NYO-tho
• γίνεται has a soft γ before ι, not a hard English g

The rhythm is quite smooth, with a natural pause after ησυχία.