Ο λογιστής μου είπε ότι η πληρωμή θα γίνει αύριο.

They are the Greek definite articles, equivalent to the.

• ο λογιστής = the accountant
• η πληρωμή = the payment

Greek uses articles very often, even in places where English might not. They also show gender, number, and case:

• ο = masculine singular nominative
• η = feminine singular nominative

Both λογιστής and πληρωμή are subjects in their own clauses, so they appear in the nominative.

Here the normal reading is my:

• ο λογιστής μου = my accountant

Greek μου can also mean to me / me, so this is a very common point of confusion. In writing, if the meaning were The accountant told me, many writers would make that clearer with μού είπε or by rephrasing.

So in this sentence, μου belongs with λογιστής, not with είπε.

είπε is the aorist (simple past) of λέω (to say / to tell), in the 3rd person singular.

So it means:

• he said
• she said
• sometimes told, depending on context

The aorist presents the action as a single completed event. It does not mean something ongoing or habitual.

ότι means that and introduces the content of what was said.

So:

• είπε ότι... = said that...

It connects the first clause to the second clause:

• Ο λογιστής μου είπε = My accountant said
• ότι η πληρωμή θα γίνει αύριο = that the payment will be made tomorrow

No.

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

In this sentence you need ότι, because it introduces a statement after είπε.

Yes. After verbs like λέω or είπε, both ότι and πως can mean that.

So this would also be possible:

• Ο λογιστής μου είπε πως η πληρωμή θα γίνει αύριο.

In many contexts:

• ότι can sound a bit more neutral or written
• πως can sound a bit more conversational

But both are very common.

θα is the particle used to form the future in Modern Greek.

So:

• θα γίνει = will happen / will be done / will take place

Unlike English, Greek does not usually make the future with a special future verb ending. It normally uses θα + verb form.

After θα, Greek uses a dependent verb form. In learner-friendly terms, you can think of γίνει as the form needed after θα for the verb γίνομαι.

So:

• να γίνει
• θα γίνει

are both normal patterns.

Here γίνει is 3rd person singular, matching η πληρωμή.

Also, do not confuse it with:

• γίνεται = is happening / happens
• θα γίνεται = will be happening / will happen regularly

In this sentence, θα γίνει is the right form for a one-time future event.

Because γίνομαι is very natural in Greek for things that happen, take place, or get carried out.

So:

• η πληρωμή θα γίνει literally feels like the payment will happen / will be carried out
• in natural English, that becomes the payment will be made

Greek often prefers this structure where English uses a passive expression.

Because Greek word order is fairly flexible, and putting αύριο at the end is very natural.

• η πληρωμή θα γίνει αύριο = neutral, straightforward
• αύριο θα γίνει η πληρωμή = stronger focus on tomorrow

So the end position here is not strange; it is just a normal way to place a time word.

No, not completely. Greek has more flexibility than English because articles and endings help show what each word is doing.

These are all possible, with slightly different emphasis:

• Η πληρωμή θα γίνει αύριο.
• Αύριο θα γίνει η πληρωμή.
• Θα γίνει αύριο η πληρωμή.

The version in your sentence is a neutral, standard one inside reported speech.

A rough pronunciation guide is:

o lo-yee-STEES moo EE-pe O-tee ee plee-ro-MEE tha YEE-nee AV-rio

More closely:

[o loʝiˈstis mu ˈipe ˈoti i pliroˈmi θa ˈʝini ˈavrio]

Stress falls on:

• λογιστής
• είπε
• ότι
• πληρωμή
• γίνει
• αύριο

A useful tip: the accent mark in Greek usually shows you which syllable gets the stress.