Ο φούρναρης λέει ότι μια καλή φραντζόλα πρέπει να είναι τραγανή απ’ έξω και μαλακή μέσα.

Λέει is the 3rd person singular present form of λέω (to say).

So:

• λέω = I say
• λες = you say
• λέει = he/she/it says

It is used here because the subject is ο φούρναρης (the baker), which is he in English terms: Ο φούρναρης λέει... = The baker says...

Ο is the masculine singular nominative definite article, meaning the.

It is ο φούρναρης because:

• φούρναρης is a masculine singular noun
• it is the subject of the sentence
• subjects normally appear in the nominative case

So:

• ο φούρναρης = the baker as the subject

A learner may also see αρτοποιός, which also means baker, but φούρναρης is a very common everyday word.

Ότι means that and introduces a clause reporting what someone says, thinks, knows, etc.

So:

• λέει ότι... = says that...

This is very natural Greek.

You may also hear πως in the same role:

• Λέει ότι...
• Λέει πως...

Both can mean He says that...

Also, learners often confuse ότι with ό,τι:

• ότι = that
• ό,τι = whatever / anything that

In this sentence, the correct form is ότι.

Μια is the feminine singular indefinite article, meaning a.

It is feminine because φραντζόλα is a feminine noun.

So:

• μια φραντζόλα = a loaf
• μια καλή φραντζόλα = a good loaf

About spelling: you may see μια or μία. Both occur. The accented form can be used for clarity or emphasis, but μια is very common in ordinary writing.

Φραντζόλα means a loaf of bread, often a full loaf rather than bread in a general sense.

This is different from:

• ψωμί = bread in general
• φραντζόλα = a loaf

So the sentence is talking about what a good loaf should be like, not bread in the abstract.

This is a very common Greek structure.

• πρέπει = it must / it should / it is necessary
• να είναι = to be in the να construction

Greek normally uses πρέπει + να + verb.

So:

• πρέπει να είναι = must be / should be

Literally, you can think of it as something like: it is necessary for it to be...

You cannot normally say just πρέπει είναι here; να is needed.

It can mean either, depending on context.

In this sentence, it is not really a legal or strict obligation. It is more like a statement of what makes a loaf good. So in natural English, both are possible:

• must be crispy outside and soft inside
• should be crispy outside and soft inside

Must sounds a bit stronger. Should sounds a bit more like advice or a standard.

They are adjectives agreeing with the feminine noun φραντζόλα.

In Greek, adjectives agree with the noun in:

• gender
• number
• case

Since φραντζόλα is feminine singular nominative, the adjectives are also feminine singular nominative:

• καλός / καλή / καλό = good
• τραγανός / τραγανή / τραγανό = crispy
• μαλακός / μαλακή / μαλακό = soft

So:

• μια καλή φραντζόλα
• να είναι τραγανή
• και μαλακή

All of those adjective forms match φραντζόλα.

Απ’ is a shortened form of από.

So:

• απ’ έξω = από έξω

This shortening happens very often before a vowel.

In this sentence:

• τραγανή απ’ έξω = crispy on the outside

Literally, έξω means outside, but with food descriptions, απ’ έξω naturally means on the outside / externally.

Because μέσα by itself can naturally mean inside.

So:

• μαλακή μέσα = soft inside

Greek often uses a balanced expression like:

• απ’ έξω ... μέσα
• outside ... inside

You could hear από μέσα in some contexts, but here μέσα alone is very natural and idiomatic.

Because Greek, like English, does not need to repeat the verb when two adjectives are linked by και.

So:

• πρέπει να είναι τραγανή απ’ έξω και μαλακή μέσα

works exactly like:

• it should be crispy outside and soft inside

Repeating it would be possible only for emphasis, but it would sound heavier:

• πρέπει να είναι τραγανή απ’ έξω και να είναι μαλακή μέσα

That is grammatical, but less natural here.

Yes, Greek word order is more flexible than English, but the version you have is the most neutral and natural.

A few points:

• μια καλή φραντζόλα is the normal order
• the adjective before the noun sounds very natural here
• τραγανή απ’ έξω και μαλακή μέσα is also a very natural descriptive order after να είναι

Greek can move words around for emphasis, but not every possible order sounds equally normal. For a learner, the sentence as given is an excellent model to follow.

A simple rough guide is:

o FOOR-na-ris LE-i O-ti mia ka-LI fran-DZO-la PRE-pi na I-ne tra-ga-NI ap EX-o ke ma-la-KI ME-sa

A few pronunciation notes:

• ού in φούρναρης sounds like oo
• ει in λέει and είναι sounds like ee
• τζ in φραντζόλα sounds like dz
• γαν in τραγανή has a normal hard g sound
• the stress matters a lot in Greek, so notice:
  • φούρναρης
  • λέει
  • καλή
  • φραντζόλα
  • πρέπει
  • τραγανή
  • μαλακή
  • μέσα