Learn Hardcore Greek: Πιστεύεις ότι συμφωνεί και η φίλη σου ή διαφωνεί; - Do you believe that your friend female also agrees or does she disagree?

ότι is the complementizer "that," introducing the clause ότι συμφωνεί.... You can also use πως after verbs like πιστεύω/νομίζω/λέω: Πιστεύεις πως συμφωνεί... The meaning is the same; πως feels a bit more informal or conversational.

What’s the difference between η and ή?

η (no accent) is the feminine definite article "the" (as in η φίλη). ή (with accent) is the conjunction "or" (as in ή διαφωνεί). The accent distinguishes them.

Why is there a semicolon at the end instead of a question mark?

In Greek, the question mark is the semicolon character ;. So ... διαφωνεί; is just the normal question mark. The Greek semicolon is a different mark, the raised dot ·.

Why don’t we repeat “she” (or the noun) in the second clause?

Greek often omits repeated subjects. After ...η φίλη σου, the second verb διαφωνεί clearly refers to the same subject. You could repeat it for emphasis: ...ή η φίλη σου διαφωνεί; or use a pronoun: ...ή αυτή διαφωνεί; but it isn’t required.

What does και mean here?

Here και means "also/too": συμφωνεί και η φίλη σου = "your friend also agrees." και can also mean "and" (εσύ και η φίλη σου) or "even," depending on context and emphasis.

Can I change the word order or move και?

Yes. All of these are idiomatic, with slightly different focus:

Πιστεύεις ότι και η φίλη σου συμφωνεί ή διαφωνεί;
Πιστεύεις ότι η φίλη σου συμφωνεί κι αυτή ή διαφωνεί;
Using "also" explicitly: Πιστεύεις ότι η φίλη σου επίσης συμφωνεί ή διαφωνεί;

Can I write κι instead of και?

Yes. και often becomes κι before a vowel sound for euphony: συμφωνεί κι η φίλη σου, κι εγώ. Writing και is always fine; κι just reflects the way it’s pronounced.

Could I say νομίζεις instead of πιστεύεις?

Yes: Νομίζεις ότι... is very common and slightly weaker/more casual ("do you think…"). Πιστεύεις can sound a bit stronger ("do you believe…") or more formal. In everyday speech they overlap a lot.

What does η φίλη σου literally mean, and where does the possessive go? What about plural/polite “your”?

Literally "the friend your"—Greek uses the article with possessives, and the enclitic possessive μου/σου/του/της/μας/σας/τους follows the noun (and any adjective): η καλή σου φίλη. For plural/polite "your," use σας: η φίλη σας. For a male friend: ο φίλος σου.

Do συμφωνεί and διαφωνεί take a preposition like “with”?

When you specify who/what someone agrees with, use με or μαζί με:

Συμφωνεί μαζί σου / με εσένα.
Διαφωνεί με εμάς. In your sentence it’s clear from context, so no object is stated.

What’s the difference between ότι and ό,τι?

ότι = "that" (complementizer): Ξέρω ότι έχει δίκιο.
ό,τι = "whatever/anything that" (indefinite): Πάρε ό,τι θέλεις.
Notice the comma in ό,τι; in our sentence you need ότι.

Why do the verbs end in -εις and -ει here?

They show person/number in the present:

πιστεύεις = 2nd person singular ("you think/believe")
συμφωνεί / διαφωνεί = 3rd person singular ("she/he/it agrees/disagrees") Mini-patterns: πιστεύω, πιστεύεις, πιστεύει; συμφωνώ, συμφωνείς, συμφωνεί.

Could I use αν instead of ότι?

No. αν means "if/whether" and introduces yes/no indirect questions: Ξέρεις αν συμφωνεί; ("Do you know whether she agrees?"). After verbs like πιστεύω/νομίζω, use ότι/πως: Πιστεύεις ότι/πως συμφωνεί;

Can I soften the second option with μήπως?

Yes: Πιστεύεις ότι συμφωνεί και η φίλη σου ή μήπως διαφωνεί; μήπως adds a tentative/polite flavor, often hinting the speaker suspects the second option.

How do I pronounce this? Where is the stress?

Stresses are marked in Greek. Rough guide: pi-STÉ-veis ó-ti sim-fo-NÍ ke i FÍ-li su í dia-fo-NÍ. Each stressed vowel in the Greek (έ, ό, εί, ή) marks the syllable you accent in speech.