Learn Hardcore Chinese: wǒ běnlái yǐwéi jīntiān de yīnyuèhuì hěn wúliáo, méi xiǎngdào jìngrán zhème yǒuyìsi. - I originally thought today’s concert would be boring, but it unexpectedly turned out to be so interesting.

以为 (yǐwéi) = “to think / assume (but be wrong)”. It already implies that the thought turned out to be incorrect.
本来 (běnlái) = “originally / at first / in the beginning”. It adds a time/background feeling.

我本来以为…… emphasizes:

this was your original expectation,
and later something happened that contradicted it.

So:

我以为今天的音乐会很无聊。
“I thought today’s concert would be boring (but it wasn’t / I was wrong).”
我本来以为今天的音乐会很无聊。
“I originally thought today’s concert would be boring (but later I discovered otherwise).”

In your sentence, 没想到竟然这么有意思 is the “later discovery” that contrasts with 本来以为.

What’s the difference between 以为, 觉得, and 认为?

These three all involve “thinking” or “feeling,” but they differ in usage and nuance:

以为 (yǐwéi)
- Means: “to think / assume but be mistaken.”
- It almost always implies that reality is different from what you thought.
- Example:
  - 我以为他是老师，其实他是学生。
    “I thought he was a teacher, but actually he’s a student.”
觉得 (juéde)
- Means: “to feel / to think (subjectively).”
- Neutral, no built‑in idea of being right or wrong.
- Often used for opinions and impressions.
- Example:
  - 我觉得这场音乐会很有意思。
    “I think this concert is interesting.”
认为 (rènwéi)
- Means: “to believe / to hold the opinion that…”.
- Sounds more formal or logical, used for more reasoned opinions.
- Example:
  - 专家认为这种方法很有效。
    “Experts believe this method is very effective.”

In your sentence, 以为 is used because the speaker’s earlier thought (“it would be boring”) turned out to be wrong.

What exactly is 今天的音乐会? Why do we need 的 there?

今天的音乐会 is a noun phrase meaning “today’s concert” / “the concert today”.

Structure: [modifier] + 的 + [noun]

今天 = today (time word, acting as a modifier)
的 = links the modifier to the noun
音乐会 = concert

So 今天的音乐会 = “the concert of today” → “today’s concert”.

Other examples:

明天的考试 – tomorrow’s exam
去年的电影 – last year’s film
学校的图书馆 – the school’s library

You could also say 今天有音乐会 (“There is a concert today”), but then 今天 modifies the verb “have” (有), not the noun “concert”. The given sentence wants to say specifically “today’s concert” as a single noun phrase.

Does 很 in 很无聊 really mean “very”? Could we drop it and just say 音乐会无聊?

In this kind of sentence, 很 (hěn) does not always strongly mean “very”. Often it functions more like a neutral link between the subject and an adjective.

今天的音乐会很无聊。
Natural, means “Today’s concert is boring.”
Depending on intonation/context it can be “is boring” or “is very boring.”
今天的音乐会无聊。
Grammatically possible, but it sounds a bit abrupt or like you’re emphasizing “boring” in a very blunt way. Native speakers usually prefer to put something (often 很) between a subject and an adjective.

Think of 很 here as:

sometimes: a real “very”
often: a “default glue word” for “Subject + adjective” sentences

Other common “glue” options: 好, 真, 太…了, etc.
But 很 + adjective is the most neutral and common.

What does 没想到 mean here? Why 没想到, not 不想到?

In this sentence, 没想到 (méi xiǎngdào) means: “I didn’t expect that…” / “I hadn’t thought that…”.

Literally: “(I) didn’t think (reach the thought that)…”
In context: introduces a result that surprises you.

Why 没 and not 不?

没 is the usual negation for past or completed actions, or for things that didn’t happen:
- 没去, 没看, 没想到.
不 is more for general, habitual, or future refusal/negation:
- 不去, 不看, 不想.

没想到 is a fixed, very common phrase; 不想到 is basically never used in this meaning.

Also, the subject 我 is omitted because it’s obvious from context. You could say:

我没想到竟然这么有意思。
Same meaning, just more explicit. The shortened 没想到 is very natural in spoken and written Chinese.

What does 竟然 add to the sentence? Could we just say 没想到这么有意思?

竟然 (jìngrán) expresses surprise or something unexpected. It’s like saying “actually”, “to my surprise”, or “unexpectedly”.

没想到这么有意思。
“I didn’t expect (it would be) so interesting.” – already shows some surprise.
没想到竟然这么有意思。
Adds extra emphasis: “I really didn’t expect it to be this interesting!”
It makes the surprise stronger and a bit more emotional.

Characteristics of 竟然:

Usually used when reality is quite different from what you would normally expect.
Can be used for positive or negative surprises:
- 他竟然记得我的生日。 – He actually remembered my birthday!
- 他竟然忘了自己的名字。 – He actually forgot his own name!

You can omit 竟然 and still be correct, but you lose that extra “wow, unexpectedly…” feeling.

What is 这么 doing in 这么有意思? How is it different from 很有意思 or 那么有意思?

这么 (zhème) is an intensifier, meaning “so / this (much)”. The pattern is:

这么 + adjective = “so + adjective”

In your sentence:

这么有意思 ≈ “so interesting”, “this interesting”

Comparisons:

很有意思
- Neutral “(very) interesting”.
- Can be mild, depending on tone.
这么有意思
- More emotional or emphatic: “so interesting!”
- Often focuses on what is close to the speaker (this thing you’re talking about now).
那么有意思
- “so / that (much) interesting”, often more distant (in time, space, or attitude) than 这么.
- Can refer to something not right in front of you:
  - 没想到那个音乐会那么有意思。
    “I didn’t expect that concert to be so interesting.”

So 竟然这么有意思 feels like “unexpectedly this interesting!” with a strong, immediate emotional tone.

What’s the nuance of 有意思 compared with 有趣 or 好玩?

All three can be translated as “interesting” in English, but they’re used slightly differently:

有意思 (yǒuyìsi)
- Common, versatile: “interesting”, “intriguing”, “enjoyable”.
- Often for things that have content, story, or some depth.
- 这本书很有意思。 – This book is interesting.
  In your sentence, 音乐会很有意思 suggests the concert was engaging/enjoyable.
有趣 (yǒuqù)
- Also “interesting”, maybe a bit more formal or bookish in some contexts.
- Often used in writing or when you want to sound a bit more literary.
- 这个话题很有趣。 – This topic is interesting.
好玩 (hǎowán)
- Literally “fun to play with”.
- More about being fun/entertaining (games, activities, toys, sometimes people).
- 这个游戏很好玩。 – This game is fun.
- 那个人很幽默，很好玩。 – That person is funny and fun to be with.

For a concert, 有意思 or 有趣 are more natural than 好玩, unless you specifically mean the experience was “fun” in a playful way.

How do we know this sentence is talking about the past if there is no 了?

Chinese doesn’t always mark past tense explicitly. Time is often understood from:

Time words (昨天, 今天, 刚才, 去年, etc.)
Context and common sense
Aspect markers like 了, 过, 在, etc.—but these are not mandatory every time.

In your sentence, several things imply a past situation:

本来以为 – “originally thought”: this by itself sets up a before vs now contrast.
没想到 – “didn’t expect”: also naturally read as past in this context.
The whole structure is clearly describing what you thought before the concert vs how it turned out.

So even without 了, a listener interprets this as a past experience:

I originally thought today’s concert would be boring, but it turned out to be surprisingly interesting.

You could add 会 (modal for future) before 很无聊 – 会很无聊 – to emphasize “would be boring,” but the time relation is already clear from context.

Could we say 我本来以为今天的音乐会会很无聊? Why is there no 会 before 很无聊 in the given sentence?

Yes, you can say:

我本来以为今天的音乐会会很无聊。

Here the second 会 (huì) is a modal verb meaning “would / will”. It clearly shows you were predicting how the concert would be:

“I originally thought today’s concert would be boring.”

In the original sentence:

我本来以为今天的音乐会很无聊

the 会 (modal) is omitted. This is still common and natural. The idea of “would be boring” is already understood from:

今天的音乐会 (today’s concert – a future or soon-to-happen event at the time of thinking), and
the contrast with what actually happened (竟然这么有意思).

So both are acceptable:

With 会: slightly more explicit prediction.
Without 会: a bit more concise, still clearly about an expectation.

Why is the time word used as 今天的音乐会 and not something like 音乐会今天?

Chinese has several ways to combine time and events. The choice changes the nuance and structure:

今天的音乐会
- “today’s concert” – a single noun phrase.
- 今天 modifies 音乐会 via 的.
- Focus is “this particular concert which takes place today”.
今天有音乐会。
- “There is a concert today.”
- 今天 modifies the existence of a concert (有), not the noun specifically.
音乐会在今天。
- “The concert is on today.”
- Emphasis is on when the concert happens.
音乐会今天很无聊。
- Grammatically possible, but sounds odd; you’d normally say:
  - 今天的音乐会很无聊。
  - or 今天的音乐会很有意思。

So 今天的音乐会 is the natural way to say “today’s concert” as the subject of the sentence.

What is the overall sentence pattern 本来以为……，没想到……?

This is a very common pattern in Chinese for expressing “I initially thought X, but it turned out Y.”

Structure:

(我) 本来以为 …，没想到 …。

Meaning:

本来以为 A，没想到 B。
“I originally thought A, (but) I didn’t expect (it would be) B.”

Your example:

我本来以为今天的音乐会很无聊，没想到竟然这么有意思。
“I originally thought today’s concert would be boring, but I didn’t expect it to be so interesting.”

Other examples:

本来以为会下雨，没想到出太阳了。
I originally thought it would rain, but I didn’t expect the sun to come out.
本来以为他不会来，没想到他提前到了。
I originally thought he wouldn’t come, but I didn’t expect he’d arrive early.

Once you learn this pattern, you’ll hear it very often in daily Chinese.

Is there any difference between 竟然 and 居然 in a sentence like this?

竟然 (jìngrán) and 居然 (jūrán) are very similar; both express surprise at something unexpected.

For your sentence, you could say:

没想到竟然这么有意思。
没想到居然这么有意思。

Both are acceptable and natural. Subtle points:

居然 is often a bit more colloquial in everyday speech, and sometimes can sound slightly stronger or more dramatic in surprise (depending on context).
竟然 can feel slightly more neutral or a bit literary/formal in some cases, but it’s also very common in spoken Chinese.

In many everyday contexts, they are interchangeable and the difference is very small.