Η μικρή τρώει μόνο την ψίχα από τη φραντζόλα και αφήνει το υπόλοιπο στο πιάτο.

Yes, μικρή is normally an adjective: the feminine singular form of μικρός, meaning small, little, or sometimes young.

Here, though, it is being used as a noun-like expression:

• η μικρή = the little one
• very often, in context, the little girl

Greek does this a lot: an adjective with the article can stand in for a person or thing that is already understood.

So instead of saying something fuller like το μικρό κορίτσι, the sentence simply says η μικρή.

Because Greek often leaves subject pronouns out when they are not needed.

The verbs already show that the subject is third person singular:

• τρώει = she/he/it eats or is eating
• αφήνει = she/he/it leaves or is leaving

Since the sentence already has η μικρή as the subject, adding αυτή for she would usually be unnecessary unless you wanted extra emphasis.

Greek definite articles change according to gender, number, and case.

In this sentence:

• η μικρή: η is feminine singular nominative, because it marks the subject
• την ψίχα: την is feminine singular accusative, because ψίχα is the direct object
• τη φραντζόλα: τη is also feminine singular accusative, after the preposition από
• το υπόλοιπο: το is neuter singular accusative, again a direct object
• στο πιάτο: το is inside the contraction στο = σε + το

So English has one main form, the, but Greek has several matching forms.

Both are forms of the feminine accusative article:

• την
• τη

The final -ν is often kept or dropped depending on the sound that follows.

A very common learner rule is:

• keep -ν before a vowel or certain consonants such as κ, π, τ, ξ, ψ and similar sounds
• often drop it before other consonants

So:

• την ψίχα keeps the -ν because ψίχα starts with ψ
• τη φραντζόλα usually drops the -ν because φραντζόλα starts with φ

You may sometimes see την φραντζόλα too, but τη φραντζόλα is very normal.

Because μόνο is limiting that specific phrase.

• τρώει μόνο την ψίχα = she eats only the crumb/soft inside

In other words, what is restricted is what she eats.

Word placement matters:

• Μόνο η μικρή τρώει... = Only the little girl eats...
• Η μικρή τρώει μόνο την ψίχα... = The little girl eats only the crumb...

So here μόνο is attached in meaning to την ψίχα.

It means from the loaf.

So την ψίχα από τη φραντζόλα is literally something like:

• the crumb/soft inside from the loaf

Here από shows the source or whole that the piece comes from.

Also, after από, Greek uses the accusative, which is why you get τη φραντζόλα.

Ψίχα literally refers to the soft inside part of bread, as opposed to the crust.

Depending on context, English might translate it as:

• crumb
• soft inside
• bread inside

So the sentence suggests that she is eating the inside of the bread and not the rest, especially not the crust.

It comes from the adjective υπόλοιπος, meaning remaining or rest.

Here it is used on its own, with the neuter article:

• το υπόλοιπο = the rest / the remainder

So, just like η μικρή, this is another case where Greek uses an adjective in a noun-like way.

In the sentence:

• αφήνει το υπόλοιπο στο πιάτο = she leaves the rest on the plate

Because στο is the normal contraction of:

• σε + το = στο

This is extremely common in Greek.

So:

• στο πιάτο = on the plate / in the plate depending on context

With αφήνει, English naturally says on the plate, but Greek uses σε for several location meanings that English splits into in, on, at, or to.

Yes, both are present tense, third person singular:

• τρώει from τρώω
• αφήνει from αφήνω

In Modern Greek, this present form can mean either:

• a general/habitual action: she eats, she leaves
• an action happening now: she is eating, she is leaving

The exact meaning depends on context. In a standalone sentence like this, English could translate it either way, depending on the situation being described.