qǐng jīntiān wánchéng zhè fèn bàogào.

In Mandarin, the subject is often omitted when it is obvious from context.

So 请今天完成这份报告。 naturally means something like Please complete this report today, with the listener understood as the person who should do it.

If you want to make the subject explicit, you can say:

请你今天完成这份报告。

That is still natural, but the original sentence sounds a little more concise and is very common in instructions, reminders, and workplace language.

Here, 请 means please and makes the sentence a polite request or instruction.

In other contexts, 请 can also mean:

• to invite
• to ask
• to request

But in this sentence, it is functioning as a politeness marker before the action.

So:

• 请今天完成这份报告。 = Please complete this report today.

It softens the command, but it can still sound firm depending on context.

Mandarin usually puts time expressions before the main verb.

A very common word order is:

Subject + Time + Verb + Object

So if we include the subject, the structure would be:

你 + 今天 + 完成 + 这份报告

That is why 今天 comes before 完成.

This is different from English, where time can often go at the end:

• English: Complete this report today
• Mandarin: 今天完成这份报告

Here, 今天 describes the action 完成. It tells you when the report should be completed.

So the meaning is:

• complete the report today

It does not mean today’s report here.

If you wanted to say today’s report, you would usually build the noun phrase differently, for example:

今天的报告 = today’s report

So:

• 今天完成这份报告 = complete this report today
• 今天的报告 = today’s report

Because Mandarin normally requires a measure word, also called a classifier, between a demonstrative and a noun.

The pattern is:

这 / 那 + measure word + noun

So:

• 这份报告 = this report

Here, 份 is the measure word.

Saying 这报告 is generally not standard Mandarin.

份 is a common measure word for documents and document-like items.

It is often used with things such as:

• 报告 = report
• 文件 = document
• 合同 = contract
• 表格 = form
• 报纸 = newspaper

So 这份报告 sounds natural because a report is treated as a document.

This is one of those word combinations learners usually need to memorize.

Yes, you may hear 这个报告, and people will understand it. But 这份报告 is usually more natural and more precise for an actual document.

A useful way to think about it is:

• 这份报告: focuses on the report as a document
• 这个报告: more general, sometimes a little less elegant or less specific

In formal or careful Mandarin, 这份报告 is the better choice here.

完成 means to complete or to accomplish. It is a fairly formal and common verb, especially for tasks, projects, and assignments.

Compared with similar expressions:

• 完成报告 = complete the report
• 写完报告 = finish writing the report
• 做完 = finish doing something

The differences are:

• 完成 is broader and more formal
• 写完 specifically emphasizes finishing the writing
• 做完 is more general and often more conversational

So 完成这份报告 can suggest finishing the whole task, not just the act of writing.

Because this sentence is a request about something that should happen in the future.

了 is often used to show a completed action or a new situation. But here, the action has not happened yet; someone is being asked to do it.

So:

• 请今天完成这份报告。 = correct for a request
• 我今天完成了这份报告。 = I completed this report today

Using 了 in the original sentence would not fit the meaning.

It sounds polite but direct.

Because it uses 请, it is not rude. However, it is still clearly an instruction, so it can sound firm, especially in a workplace, school, or administrative setting.

Tone depends a lot on context:

• from a boss or teacher: normal instruction
• in an email: polite and efficient
• between close friends: possibly a bit formal or stiff

If you want to make it softer, you could say things like:

• 请你今天完成这份报告。
• 麻烦你今天完成这份报告。

The second one sounds more gentle and indirect.

Yes, in some cases you can, but the emphasis may change.

For example:

• 请今天完成这份报告。
• 今天请完成这份报告。

Both are possible.

The original version is very natural and neutral.
Putting 今天 first can add a little more emphasis to today.

However, you normally would not put 今天 after the object in this kind of sentence:

• 请完成这份报告今天。 = unnatural

So for learners, the safest pattern is:

请 + 时间 + 动词 + 宾语

which here gives:

请今天完成这份报告。