هذه نزهة.

Because نزهة is a grammatically feminine singular noun, and the demonstrative has to match it.

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

Even though نزهة is not a female person, it is still treated as feminine in grammar.

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

So Arabic says:

• هذه نزهة literally: this outing/picnic

but it means:

• This is an outing/picnic

This kind of sentence is called a nominal sentence.

Because here the sentence means This is an outing/picnic, where نزهة is indefinite.

If you said:

• هذه النزهة

that would usually mean:

• this outing/picnic

So there is an important difference:

• هذه نزهة = This is an outing/picnic
• هذه النزهة = this outing/picnic

In other words, the first is a full sentence, while the second is usually a noun phrase.

Grammatically:

• هذه = the subject/topic of the sentence
• نزهة = the predicate / the thing being said about it

So the structure is basically:

• This
  • an outing/picnic

In traditional Arabic grammar, you can think of them as:

• هذه = مبتدأ
• نزهة = خبر

That final ـة is called taa marbuuTa (تاء مربوطة). It often marks a noun as feminine.

In this word, it helps show that نزهة is feminine, which is why the sentence uses هذه.

Pronunciation note:

• in pause, it usually sounds like -ah
• when grammar endings are pronounced, it can sound like -at

So نزهة can sound like:

• nuzhah in pause
• nuzhatun with full case ending

It would normally be:

• هٰذِهِ نُزْهَةٌ

The ـٌ ending on نزهةٌ is called tanween and shows that the noun is:

• indefinite
• nominative

That nominative ending is used because نزهة is the predicate of a nominal sentence.

In everyday writing, short vowels and tanween are usually omitted, so you often just see:

• هذه نزهة

A careful MSA pronunciation is:

• hādhihi nuzhatun

If you pause at the end, it is often pronounced more like:

• hādhihi nuzhah

A few pronunciation tips:

• ذ sounds like the th in this
• هٰذِهِ = hā-dhi-hi
• نُزْهَة = nuz-ha(h)

No. This is grammatical gender, not biological sex.

Arabic nouns are classified as masculine or feminine, and many non-human things are feminine. نزهة is one of those feminine nouns.

So in this sentence, هذه is feminine because the noun نزهة is grammatically feminine, not because the outing itself is female.

In standard Arabic, no. That would be a gender mismatch.

Because نزهة is feminine, the correct demonstrative is:

• هذه نزهة

Using هذا would sound ungrammatical in MSA.

They are different structures:

• هذه نزهة = a sentence: This is an outing/picnic
• هذه النزهة = a phrase: this outing/picnic

So when the noun is indefinite with no الـ, you usually get a sentence meaning This is ...
When the noun is definite with الـ, you usually get a phrase meaning this ...

That distinction is very common in Arabic and very useful to notice early.