هذه حفلة.

هذه means this for a feminine noun.

In Modern Standard Arabic, it is pronounced hādhihi.

A rough breakdown is:

• hā = long haa
• dhi = like thi in this, but with a voiced sound
• final hi = a short hi

So the whole sentence is read roughly as hādhihi ḥaflah in pause.

Because حفلة is a feminine noun.

Arabic demonstratives must match the gender of the noun:

• هذا = this for masculine
• هذه = this for feminine

Since حفلة ends in ة (taa marbuuTa), that is a very common sign that the noun is feminine, so Arabic uses هذه.

In Arabic, the verb to be in the present tense is usually not written or spoken in simple sentences like this.

So:

• هذه حفلة. = This is a party.

Literally, Arabic is just saying:

• this party

But the meaning is understood as This is a party.

This is very normal in Arabic nominal sentences.

If you wanted the past tense, Arabic would use a verb:

• كانت هذه حفلةً = This was a party

Because حفلة here means a party, not the party.

In Arabic:

• حفلة = a party
• الحفلة = the party

So:

• هذه حفلة. = This is a party.
• هذه الحفلة. = This is the party / This party

That difference is very important.

They look similar, but they are grammatically different.

هذه حفلة

This is a full sentence:

• هذه = the subject, this
• حفلة = the predicate, a party

Meaning:

• This is a party.

هذه الحفلة

This is usually a noun phrase:

• هذه = this
• الحفلة = the party

Meaning:

• this party

So the presence or absence of الـ changes the structure and meaning.

حفلة is pronounced roughly ḥaflah when you stop at the end of the word.

A few pronunciation notes:

• ح is a strong breathy h sound, deeper than English h
• ف = f
• ل = l
• final ة usually sounds like -a or -ah when pausing

So in normal pause pronunciation:

• حفلة → ḥaflah

But if the word is followed by a grammatical ending or attached in certain contexts, the ة can sound like t:

• حفلةٌ → ḥaflatun
• حفلة جميلة → often underlyingly ḥaflatun jamīlah

This is a very common feature of words ending in ة.

Yes, in fully vocalized formal Arabic there is a case ending on حفلة.

The fully marked form is:

• هذه حفلةٌ

Here, حفلةٌ has tanwīn ḍamm (-un) because it is the predicate of a nominal sentence and is nominative.

However, in normal reading and in most everyday pronunciation, learners often hear or say:

• هذه حفلة

without pronouncing the final -un.

Also, هذه itself does not change here in the same visible way; the main audible case ending is on حفلةٌ.

Because the normal standard way to say This is a party is:

• هذه حفلة

Arabic commonly puts the demonstrative first in this kind of sentence.

So the pattern is:

• هذا كتاب = This is a book
• هذه سيارة = This is a car
• هذه حفلة = This is a party

A form like حفلة هذه would not be the normal Modern Standard Arabic way to express this meaning.

Yes, if هذه means this and directly relates to a noun, that noun should be feminine.

Examples:

• هذه بنت = This is a girl
• هذه مدرسة = This is a school
• هذه حفلة = This is a party

For a masculine noun, Arabic normally uses هذا:

• هذا كتاب = This is a book

So this sentence is also a good reminder that حفلة is grammatically feminine.

Not usually.

In this exact form, هذه حفلة is best understood as:

• This is a party

If you want this party, Arabic normally says:

• هذه الحفلة

So even though Arabic often leaves out is, you should still understand هذه حفلة as a sentence, not just a noun phrase.

It is a nominal sentence.

A nominal sentence in Arabic begins with a noun, pronoun, or demonstrative rather than with a verb.

Here:

• هذه = the topic/subject part
• حفلة = the comment/predicate part

So the structure is:

• this
  • a party
• meaning: This is a party

This is one of the most basic and common Arabic sentence patterns.