yīnwèi míngtiān yào zuò bàogào, wǒ jīntiān wǎnshang bùdébù zài jiā jìxù zhǔnbèi.

因为 means because, so it introduces the reason:

• 因为明天要做报告 = Because I have to give a report tomorrow

Chinese often puts the reason first and the main result after it, just like:

• Because X, Y

So the sentence structure is:

• 因为
  • reason, + result

That is very natural in Mandarin.

It can be there, but it does not have to be.

A very common pattern is:

• 因为……，所以…… = Because..., therefore...

So you could also say:

• 因为明天要做报告，所以我今天晚上不得不在家继续准备。

In everyday Mandarin, people often omit 所以 when the meaning is already clear.
So the original sentence is completely natural.

Here 要 means something like:

• need to
• have to
• am going to

In 明天要做报告, it does not mainly mean want to. It means the speaker has a scheduled obligation or plan:

• 明天要做报告 = I have to / am going to give a report tomorrow

So 要 often depends on context. It can mean:

• to want
• to need to / be going to

Here it clearly expresses an upcoming task.

In Mandarin, 做报告 is a common expression meaning:

• to give a report
• to present a report

This is a matter of normal Chinese word choice, not a literal word-for-word translation from English.

Common collocations include:

• 做报告 = give a report / make a presentation
• 作报告 = same meaning; a slightly more formal written variant

Even though 说 means to say / speak, Chinese usually does not say 说报告 for this meaning.

不得不 means:

• have no choice but to
• cannot avoid
• must, whether one wants to or not

So:

• 我今天晚上不得不在家继续准备 = I have no choice but to stay home tonight and continue preparing

It often implies reluctance or pressure from the situation.

Compare:

• 必须 = must, have to
• 不得不 = have no choice but to

不得不 feels stronger emotionally, as if circumstances are forcing the action.

This is one of those patterns that does not translate word-for-word well.

Historically and grammatically, 不得不 functions as a fixed expression meaning:

• cannot not
• therefore, have to

So although it literally looks like multiple negatives, the whole phrase means:

• must
• have no choice but to

You should learn 不得不 as one chunk rather than trying to interpret each character separately every time.

Chinese usually places time expressions early in the sentence, often before the main verb phrase.

So this order is very natural:

• 我今天晚上不得不在家继续准备

Breakdown:

• 我 = subject
• 今天晚上 = time
• 不得不 = modal / attitude
• 在家 = location
• 继续准备 = main action

A common Chinese word-order pattern is:

• Subject + Time + Modal/Adverb + Place + Verb

That is why 今天晚上 comes before 不得不.

在家 gives the location of the action, and in Chinese, location usually comes before the main verb.

So:

• 在家继续准备 = continue preparing at home

This follows a common pattern:

• 在 + place + verb

Examples:

• 在学校学习 = study at school
• 在办公室工作 = work at the office
• 在家准备 = prepare at home

So 在家 naturally appears before 继续准备.

Yes, both are possible, but the emphasis is slightly different.

• 在家继续准备: the location at home is introduced first
• 继续在家准备: the sense of continuing is highlighted a little earlier

In many contexts, both sound natural.
The original sentence, 在家继续准备, is very standard and smooth.

继续 means to continue, and 准备 means to prepare.

So:

• 继续准备 = continue preparing

It means the speaker has probably already started preparation and needs to keep working on it.

You may also hear:

• 继续做准备

This is also correct and means almost the same thing.
The shorter 继续准备 is very natural.

Chinese grammar does not work the same way as English infinitives.

In English, we often need:

• to prepare
• to do
• to study

In Chinese, verbs can often follow each other directly:

• 继续准备 = continue preparing
• 想去 = want to go
• 要做 = need to do

So no extra word is needed between 继续 and 准备.

In careful dictionary-style pronunciation, it is often written:

• wǎnshàng

But in everyday speech, the second syllable is very often a neutral tone:

• wǎnshang

That is why your sentence shows wǎnshang.

Both are related, but the neutral-tone pronunciation is extremely common in normal conversation.

The comma separates the reason from the main statement:

• 因为明天要做报告，
• 我今天晚上不得不在家继续准备。

This is very common in Chinese writing. It helps show the pause between:

1. the reason
2. the consequence/result

It works much like a pause in English after a long introductory clause.

Yes, that is also possible.

For example:

• 我今天晚上不得不在家继续准备，因为明天要做报告。

This means the same thing:

• I have to stay home tonight and continue preparing, because I have to give a report tomorrow.

Both word orders are natural.
The version with 因为 at the beginning feels a bit more like the speaker is setting up the reason first.

In this sentence, 做报告 usually means an oral report / presentation, not just writing a document.

Depending on context, 报告 can refer to:

• a report
• a presentation
• a formal talk

So 明天要做报告 most naturally suggests:

• I have to give a presentation / make a report tomorrow

If the speaker meant writing a report, Chinese would usually make that clearer in another way.

Sometimes, but the nuance is different.

• 报告 often suggests a report, presentation, or more formal work-related/school-related briefing
• 演讲 means speech or public speech

So if you are presenting findings in class or at work, 做报告 is often better.
If you are giving a more formal speech to an audience, 演讲 may be better.

They overlap sometimes, but they are not always interchangeable.

Yes, sometimes Chinese can omit the subject if it is obvious from context.
But in a full sentence like this, including 我 is natural and clear.

• 我今天晚上不得不在家继续准备。

Without 我, the sentence could still be understood in the right context, but it may sound less complete by itself.

Chinese often drops pronouns in conversation, but written or stand-alone sentences usually keep them when helpful.

不得不 is completely natural and common, but it is a little more deliberate than some simpler alternatives.

Compare:

• 不得不 = have no choice but to
• 必须 = must
• 只好 = have no alternative but to; might as well

Examples:

• 我必须准备。 = I must prepare.
• 我不得不准备。 = I have no choice but to prepare.
• 我只好准备。 = I have no alternative but to prepare.

So 不得不 is not unnatural at all; it just adds the feeling of being forced by circumstances.

A helpful way to see it is:

• 因为明天要做报告， = reason
• 我 = subject
• 今天晚上 = time
• 不得不 = modal expression
• 在家 = place
• 继续准备 = action

So the pattern is roughly:

• Because + reason, subject + time + modal + place + verb

That is a very typical Mandarin structure.
If you get used to this order, many similar sentences will feel much easier.