zhè piān zuòwén hěn zhòngyào.

In sentences like 这篇作文很重要, 很 has two roles:

1. Grammatical role (linking):
   In Mandarin, when an adjective is used as the predicate (i.e., “is important,” “is big”), it usually needs a degree word in front.
   Pattern: Subject + 很 + Adjective
   So 这篇作文很重要 is the normal, neutral way to say “This composition is important.”

2. Degree meaning:
   Often 很 is not as strong as English “very.” In everyday speech it’s closer to a neutral “is” plus a light degree, something like “quite / really / is (adj).”

   • 他很高。 = He’s tall. (not necessarily “very tall,” just “tall”)

If you really want to emphasize “very,” you can use stronger words like 非常, 特别, or 挺…的:

• 这篇作文非常重要。 – This composition is very / extremely important.
• 这篇作文特别重要。 – This composition is especially important.

You can say 这篇作文是很重要, but it’s not the neutral, default form.

• 这篇作文很重要。 – Simple statement, neutral: “This composition is important.”

• 这篇作文是很重要，… – Often used when:

  • you’re contrasting it with something else, or
  • you’re emphasizing that “indeed, it is very important” (often followed by a “but/however”).

  Example:

• 这篇作文是很重要，不过你也不要太紧张。
  “This composition is important, but you also shouldn’t be too nervous.”

For a plain statement, drop 是 and just use Subject + 很 + Adjective.

In Chinese, adjectives can function as verbs (they’re often called stative verbs). So:

• English: This composition is important.
• Chinese: 这篇作文很重要。 (literally: “This composition very-important.”)

You only use 是 to link nouns or noun phrases:

• 他是老师。 – He is a teacher.
• 北京是中国的首都。 – Beijing is the capital of China.

But with adjectives, the basic pattern is:

• Subject + (degree word, often 很) + Adjective
  
  • 天气很冷。 – The weather is cold.
  • 他很聪明。 – He is smart.
  • 这篇作文很重要。 – This composition is important.

篇 (piān) is a measure word specifically used for texts that are pieces of writing, such as:

• 一篇文章 – an article
• 一篇日记 – a diary entry
• 一篇小说 – a (short) story
• 一篇作文 – a composition / essay (typically a student’s writing)

So 这篇作文 literally means “this piece (篇) of composition.”

Using 个 (这个作文) is grammatically incorrect in standard Mandarin, because 个 is a general measure word and doesn’t match the “type” of noun here. In casual speech some people might occasionally throw 个 around more freely, but you should learn and use 篇 with 作文.

Both involve written texts, but they’re used in different contexts:

• 作文 (zuòwén)

  • Usually means a school composition / essay, especially something a student writes as an assignment.
  • Common in school contexts: 写作文, 语文作文.

• 文章 (wénzhāng)

  • More general: article, piece of writing, essay.
  • Can be news articles, blog posts, academic essays, literary pieces, etc.

So:

• 这篇作文很重要。 – This (school) composition is important (e.g., exam essay).
• 这篇文章很重要。 – This article / piece of writing is important (could be in a book, news site, etc.).

Yes, you can say 作文很重要, but the meaning shifts:

• 这篇作文很重要。
  Refers to a specific composition: “This (particular) composition is important.”
  You’re pointing to one concrete piece of writing.

• 作文很重要。
  More general: “(Writing) compositions is important” or “Composition (as a subject) is important.”
  It sounds like you’re talking about composition in general, for example as part of language learning or education.

So 这 makes it clearly one specific composition you have in mind.

Yes, it’s natural to analyze it that way:

• Topic: 这篇作文 – “As for this composition…”
• Comment: 很重要 – “…(it) is important.”

Chinese is often described as a topic-prominent language, and sentences like this are very typical:

• 这个问题很难。 – As for this question, (it) is difficult.
• 这件事很麻烦。 – As for this matter, (it) is troublesome.
• 这篇作文很重要。 – As for this composition, (it) is important.

You don’t need to do anything special for this; it’s just how Chinese naturally structures many sentences.

The natural negative forms are:

• 这篇作文不重要。 – This composition is not important.
• 这篇作文不太重要。 – This composition is not very important / not that important.

不很重要 is grammatically possible but sounds a bit odd or literary; it often implies “not very important” with a subtle, slightly formal flavor. In everyday speech:

• Use 不重要 to say it’s simply “not important.”
• Use 不太重要 to soften it: “not very important / not so important.”

Chinese usually does not mark tense on the verb or adjective. You show time with context words:

• 那篇作文很重要。 – That composition was important. (if you’re talking about past events)
• 那时候，这篇作文很重要。 – At that time, this composition was important.
• 以前，这篇作文很重要。 – Before / in the past, this composition was important.

To ask:

• 这篇作文重要吗？ – Is / Was this composition important? (time depends on context)
  If you clearly set the time in the past:

• 那次考试里，这篇作文很重要吗？
  “In that exam, was this composition important?”

Chinese relies heavily on time expressions (那时候, 以前, 那次考试里) and context instead of verb tense changes.

You have two main options:

1. 这篇作文重要吗？

   • Natural, neutral: “Is this composition important?”
   • Here you usually drop 很.

2. 这篇作文很重要吗？

   • Often implies surprise, doubt, or seeking confirmation:
     “Is this composition really very important?”
   • You’re questioning the degree (how important) more than just “important or not.”

So for a straightforward yes/no question, 这篇作文重要吗？ is the usual form.

They differ in sentence structure and focus:

1. 这篇作文很重要。

   • Predicate sentence: “This composition is important.”
   • Structure: [Subject: 这篇作文] + [Predicate: 很重要].

2. 这篇很重要的作文

   • Noun phrase: “this very important composition.”
   • Structure: [这篇 + 很重要的] + 作文
   • 很重要的 is an adjective phrase modifying 作文.

Usage:

• 这篇作文很重要。 – a full sentence.
• 这篇很重要的作文是明天要交的。 – “This very important composition is due tomorrow.” (here, 这篇很重要的作文 is just the subject of the sentence)

So the first states a fact about the composition; the second uses “very important” as an attributive description inside a bigger noun phrase.