Η αναβολή της συνάντησης δεν μας βοήθησε πολύ, γιατί η προθεσμία για την υποβολή μένει η ίδια.

Because the Greek definite article changes for gender, number, and case.

In this sentence:

• η αναβολή = the postponement
  
  • η is feminine singular nominative
• της συνάντησης = of the meeting
  
  • της is feminine singular genitive
• την υποβολή = the submission
  
  • την is feminine singular accusative

English uses just the, but Greek shows more grammatical information in the article.

The genitive is often used to mean of ....

So:

• η αναβολή = the postponement
• της συνάντησης = of the meeting

Together, η αναβολή της συνάντησης means the postponement of the meeting.

This is a very common Greek pattern:
noun + genitive noun = a relationship like of, possession, association, etc.

δεν is the basic negation word used before verbs in many tenses.

So:

• βοήθησε = helped
• δεν βοήθησε = did not help

In this sentence:

• δεν μας βοήθησε πολύ = it didn’t help us much

μας here means us. It is a weak object pronoun, and in Greek these pronouns normally come before the verb.

So:

• μας βοήθησε = helped us

You could compare:

• βοήθησε εμάς = possible, but more emphatic
• μας βοήθησε = the normal neutral order

So the sentence uses the standard Greek placement.

βοήθησε is the aorist form of βοηθώ / βοηθάω, and here it expresses a single completed past event:

• Η αναβολή ... δεν μας βοήθησε πολύ
  = The postponement ... didn’t help us much

This fits the idea well: the postponement happened, and we are evaluating its effect as one completed fact.

If Greek used the imperfect instead, it would suggest something more ongoing or repeated, which is not the idea here.

Because πολύ here is an adverb, not an adjective.

It modifies the verb βοήθησε:

• δεν μας βοήθησε πολύ = didn’t help us much / very much

By contrast, πολλά is usually many / a lot with plural nouns, for example:

• πολλά προβλήματα = many problems

So in this sentence, πολύ is the correct form.

It can mean both, depending on context.

Here it means because:

• ..., γιατί η προθεσμία ... μένει η ίδια.
• ..., because the deadline remains the same.

When it means why, it usually appears in a question:

• Γιατί άργησες; = Why were you late?

So the surrounding structure tells you which meaning is intended.

This means for the submission.

• για = for
• την υποβολή = the submission

So:

• η προθεσμία για την υποβολή = the deadline for the submission

This is a natural Greek way to express purpose or relation.

You may also see more compact alternatives in Greek, such as:

• η προθεσμία υποβολής

That also means the submission deadline / the deadline for submission. The version in your sentence is just slightly more explicit.

Because the sentence is describing a current situation that still holds true now.

• μένει = remains / stays

So the idea is:

• the meeting was postponed in the past,
• but the deadline is still unchanged now.

That is why the second clause uses the present tense.

Both can work, but μένει η ίδια is more precise here.

• είναι η ίδια = is the same
• μένει η ίδια = remains the same / stays the same

Using μένει emphasizes that even after the postponement, nothing changed about the deadline. That nuance is important in this sentence.

Here η ίδια means the same.

It agrees with η προθεσμία, which is feminine singular, so Greek uses the feminine singular form:

• masculine: ο ίδιος
• feminine: η ίδια
• neuter: το ίδιο

So:

• η προθεσμία μένει η ίδια = the deadline remains the same

This is a very common use of ίδιος in Greek.

Yes. It breaks down like this:

• Η αναβολή της συνάντησης
  = The postponement of the meeting
• δεν μας βοήθησε πολύ
  = didn’t help us much
• γιατί
  = because
• η προθεσμία για την υποβολή
  = the deadline for the submission
• μένει η ίδια
  = remains the same

So the full structure is:

[main statement] + γιατί + [reason]

That is a very common Greek sentence pattern.