Ένα καλό πρωινό μου δίνει δύναμη για όλη τη μέρα.

Ένα is the neuter singular form of the indefinite article, meaning a or an.

It is used because πρωινό is a neuter singular noun. So:

• ένα πρωινό = a breakfast

Greek articles must agree with the noun in gender, number, and case.

The adjective καλός changes form to match the noun it describes.

Since πρωινό is neuter singular, the adjective must also be neuter singular:

• masculine: καλός
• feminine: καλή
• neuter: καλό

So:

• ένα καλό πρωινό = a good breakfast

Here, πρωινό means breakfast.

The word comes from the idea of morning, and in modern Greek το πρωινό commonly means breakfast.

So in this sentence:

• Ένα καλό πρωινό = A good breakfast

Μου means to me or my, depending on context. In this sentence it means to me.

So:

• μου δίνει = gives me

Greek often uses a weak pronoun like μου before the verb. This is very common.

Compare:

• μου δίνει δύναμη = it gives me strength

Even though English puts me after the verb, Greek usually places μου before it.

Because the subject is already expressed by Ένα καλό πρωινό.

Greek does not need an extra word like it here. The noun phrase at the beginning is the subject:

• Ένα καλό πρωινό = the thing doing the action
• μου δίνει = gives me

So the full structure is:

• A good breakfast
  • gives me
    • strength

Δίνει is the 3rd person singular present tense of δίνω, meaning to give.

So:

• δίνω = I give
• δίνεις = you give
• δίνει = he/she/it gives

Here it matches the singular subject Ένα καλό πρωινό:

• Ένα καλό πρωινό μου δίνει...
• A good breakfast gives me...

Greek often leaves out the article with abstract nouns when speaking in a general sense.

Δύναμη means strength, and here it is being used as a general idea, not as a specific, identified strength.

So:

• μου δίνει δύναμη = it gives me strength

This is natural Greek. You could sometimes see an article with abstract nouns in other contexts, but here no article is the normal choice.

Δύναμη is in the accusative singular, because it is the direct object of δίνει.

The verb δίνει gives something, and that something is δύναμη.

So:

• subject: Ένα καλό πρωινό
• indirect object: μου
• direct object: δύναμη

In form, δύναμη looks the same as the nominative for this noun, but its role in the sentence is accusative.

Literally, it means something like:

• for all the day
• more naturally: for the whole day or all day long

Breaking it down:

• για = for
• όλη = whole / all
• τη μέρα = the day

So:

• για όλη τη μέρα = for the whole day

Because μέρα is a feminine singular noun, so the adjective όλος must agree with it.

Forms of όλος include:

• masculine singular: όλος
• feminine singular: όλη
• neuter singular: όλο

Since μέρα is feminine:

• όλη τη μέρα = the whole day

Both are related to the same article: την.

Before a word beginning with certain consonants, especially in everyday speech and writing, την is often shortened to τη.

So:

• την μέρα
• τη μέρα

Both can occur, but τη μέρα is very common and natural.

After για, Greek uses the accusative.

So τη μέρα is accusative singular.

You can think of:

• για τη μέρα
• for the day

This is a very common preposition-case combination in Greek.

Yes. Greek word order is more flexible than English word order.

The neutral, natural order here is:

• Ένα καλό πρωινό μου δίνει δύναμη για όλη τη μέρα.

But Greek can move things around for emphasis. For example:

• Μου δίνει δύναμη για όλη τη μέρα ένα καλό πρωινό.

This is less neutral and gives a different emphasis, but it is still understandable.

For learners, the original order is the best one to use.

A rough pronunciation guide is:

Éna kaló pro-inó mou dín-i dýnami ya óli ti méra

A few helpful notes:

• Ένα = EH-na
• καλό = ka-LO
• πρωινό = pro-i-NO
• μου = moo
• δίνει = THEE-ni or DHEE-ni, depending on how you approximate δ
• δύναμη = THY-na-mi or DHY-na-mi
• για = ya
• όλη = O-li
• τη μέρα = ti ME-ra

The stressed syllables are marked by the written accents in Greek.

It is most naturally understood as a general statement:

• A good breakfast gives me strength for the whole day.

It does not usually mean one particular breakfast on one particular day. The use of ένα καλό πρωινό here is similar to English general statements with a:

• A healthy breakfast helps a lot.

So the sentence expresses a general truth or habit.