تبدأ ليلة جديدة الآن.

It is a verbal sentence, so it starts with a verb.

Breakdown:

• تبدأ = begins / is beginning
• ليلة = night
• جديدة = new
• الآن = now

So the pattern is:

verb + subject + adjective + time expression

Arabic often uses this kind of verb-first order.

Because ليلة is a feminine singular noun.

In the present tense:

• يبدأ = he/it begins for a masculine subject
• تبدأ = she/it begins for a feminine subject

Since ليلة is grammatically feminine, the verb must be feminine too:

• تبدأ ليلة جديدة الآن

If the subject were masculine, you would use يبدأ, for example:

• يبدأ يوم جديد الآن = A new day begins now

Yes. By itself, تبدأ can also mean you begin when speaking to one male.

So out of context, تبدأ could mean either:

• she/it begins
• you begin (masculine singular)

But in this sentence, the noun ليلة جديدة comes after it, so that tells you تبدأ means it begins, referring to ليلة.

It is the present/imperfect form.

In Arabic, this form can express:

• present
• ongoing action
• sometimes near future, depending on context

Here, because of الآن (now), the meaning is clearly present:

• begins now
• is beginning now

The dictionary form is بدأ = to begin / to start.

Its root is:

• ب د أ

So:

• بدأ = he began
• تبدأ = she/it begins or you begin (masculine singular)

The final ء is a hamza, and that is part of the root.

Because ليلة is indefinite here, so it means a night.

• ليلة جديدة = a new night
• الليلة الجديدة = the new night

Also, الليلة very often means tonight in modern usage, depending on context.

So adding الـ would change the meaning.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• ليلة جديدة = a new night

Not the other way around.

Also, the adjective must agree with the noun in:

• gender
• number
• definiteness
• case

Since ليلة is:

• feminine
• singular
• indefinite

جديدة matches it exactly.

That ة is the taa marbuuTa (ة), which often marks a feminine noun or adjective.

Since ليلة is feminine, the adjective describing it also has to be feminine:

• جديد = new (masculine)
• جديدة = new (feminine)

So جديدة is used because it describes the feminine noun ليلة.

In full formal grammar, both are nominative here.

Fully vowelled, the sentence would be:

• تبدأُ ليلةٌ جديدةٌ الآنَ

Why nominative? Because ليلة جديدة is the subject phrase of the verbal sentence.

In normal Arabic writing, these case endings are usually not written, and in everyday speech or relaxed reading they are often not pronounced.

Yes, it can move.

الآن is a time expression meaning now, and Arabic allows some flexibility with adverbs.

This sentence:

• تبدأ ليلة جديدة الآن

could also be:

• الآن تبدأ ليلة جديدة

Both are correct.

The version with الآن at the end sounds very natural and neutral. Putting الآن at the front gives now a bit more emphasis.

In careful formal pronunciation with full case endings:

tabdaʾu laylatun jadīdatun al-ʾāna

In less formal reading, many speakers would say something closer to:

tabdaʾ layla jadīda al-ān

A few pronunciation notes:

• تبدأ contains a hamza (ء), a glottal stop
• ج in MSA is usually taught as j
• الآن is pronounced roughly al-ān

• ليلة = a night / one night
• ليل = night / nighttime in a more general sense

So:

• تبدأ ليلة جديدة الآن = A new night begins now

If you used ليل, the meaning would be more general or abstract, not one night as a unit.

Yes. That is also possible.

• تبدأ ليلة جديدة الآن = verb-first, a very common Arabic verbal sentence
• ليلة جديدة تبدأ الآن = noun first, with slightly different emphasis

The meaning is basically the same, but the sentence feels a little different in focus. The original version is very natural in standard Arabic.