Learn Hardcore Chinese: wǒ jīntiān tài lèi le, shòubuliǎo. - I’m too tired today; I just can’t stand it.

But in everyday speech, 太…了 is also used just to strongly emphasize an adjective, sometimes almost like “so / really” without a strong “excessive” feeling, especially with positive adjectives:

太好了！ – That’s great!
太漂亮了！ – So pretty!

In 太累了, there is a complaining / overwhelmed feeling: “I’m (just) too tired (today).”
So: 太 here is both “very” and “too” in a natural English sense, with a strong emotional tone.

Why is there a 了 after 累? Is it past tense?

The 了 after 累 here is sentence-final 了, not simple past tense.

Its main functions in this sentence:

Marks a new situation / change of state
It implies: “Now (today), I’ve become very tired (I wasn’t like this before).”
Adds an exclamatory / emotional tone
Compare:
- 我今天很累。 – I’m very tired today. (quite neutral)
- 我今天太累了。 – I’m just too tired today! (stronger feeling / complaint)

So 太累了 is not “was too tired”; it’s more like “am now too tired / have gotten too tired”.

Chinese doesn’t have a tense system like English; 了 here is not a simple “past tense marker” but a particle showing a new or current state, plus emotion.

Can I say 我今天太累 without 了? Is that wrong?

You can hear 我今天太累 in speech, but:

The most natural, common pattern is 太 + adj + 了.
Without 了, 我今天太累 can sound a bit unfinished or less expressive.

Rough comparison:

我今天太累了。 – Very natural, sounds complete and emotional.
我今天太累。 – Understandable, but tends to feel like something is missing, or like casual clipped speech.

For learners, it’s better to stick with 太累了 as a fixed pattern.

What’s the difference between 我今天太累了 and 我今天很累?

Both describe being tired, but the tone and strength are different.

我今天很累。
- “I’m very tired today.”
- Neutral, factual, less emotional.
- Could just be reporting your condition.
我今天太累了。
- “I’m too tired today / I’m just so tired today.”
- Stronger, more emotional, often complaining or overwhelmed.
- Implies this tiredness is a problem for you.

In your full sentence, 我今天太累了，受不了。, the 太 matches well with 受不了: being so / too tired that you can’t take it.

How is 受不了 built, and what exactly does it mean?

受不了 (shòu bù liǎo) is a verb–complement structure:

受 – to bear, to stand, to endure, to take (pressure, pain, situation, etc.)
不 – negative marker
了 (liǎo) – here this is not the sentence-final 了; it is a result complement meaning “able to finish / manage”.

Together 受不了 literally means “cannot endure / cannot manage to bear”, so naturally:

“can’t take it”
“can’t stand it”
“can’t bear it”

The positive form exists too:

受得了 – “can stand it / can take it”

In your sentence, 受不了 means the speaker is so tired that they cannot handle it anymore.

Why is there no subject before 受不了? Should it be 我受不了?

It could be 我受不了, but in Chinese it’s very common to omit the subject in the second clause if it’s clearly the same as the first clause.

我今天太累了，受不了。
= 我今天太累了，我受不了。

Because 我 is already given in the first clause, Chinese doesn’t need to repeat it. Native speakers often drop repeated subjects like this to make speech more concise and natural.

For a learner, both are acceptable, but the version without the second 我 sounds more native-like in casual speech.

Can I say 我今天太累了，受不了了? What’s the difference?

Yes, 我今天太累了，受不了了。 is very natural.

Here’s what’s going on:

受不了 is already “can’t stand (it)”.
Adding the sentence-final 了 after that (受不了 + 了) emphasizes “(I) can’t stand it now / anymore” and adds emotional force.

Nuance:

我今天太累了，受不了。
– I’m too tired today; I can’t stand it. (already emotional)
我今天太累了，受不了了。
– I’m too tired today; I really can’t take it anymore. (even more urgent / dramatic)

Both are correct; with the extra 了 at the end, the second clause feels a bit more intense.

Can 受不了 take an object? For example, “I can’t stand this heat”?

Yes. 受不了 often takes an object.

Examples:

我受不了这么热的天气。
I can’t stand such hot weather.
我受不了他。
I can’t stand him.
这工作太累人了，我受不了。
This job is too exhausting; I can’t stand it.

In your sentence, the object is implicit:

我今天太累了，受不了。
→ “I’m too tired today, I can’t stand this situation / this level of tiredness.”

Why is the word order 我今天太累了, not 今天我太累了? Are both correct?

Both are correct:

我今天太累了。
今天我太累了。

General rules:

Time words like 今天, 明天, 现在 usually appear early in the sentence, often right after the subject or at the very beginning.
Changing between 我今天… and 今天我… is usually just a slight difference in emphasis / rhythm, not grammar.

Nuance (very slight):

我今天太累了。 – Slightly more focus on “I” as the topic.
今天我太累了。 – Slightly more focus on “today” as the time frame.

In everyday conversation, 我今天太累了 is very common and completely natural.

Is this sentence formal or informal? When is it appropriate to use?

我今天太累了，受不了。 is informal, spoken language.

You’d say this to:

friends
family
close coworkers
people you’re comfortable with

In a formal context (e.g., email to your boss), you might use something a bit softer or more neutral, for example:

我今天有点儿累，可能状态不太好。
I’m a bit tired today; I may not be in the best shape.

But among people you know well, the original sentence is perfectly natural and common.

How do you pronounce 受不了 correctly? Is it shòu bù liǎo or shòu bú liǎo?

Standard pronunciation is:

受不了 – shòu bù liǎo
- 受 – shòu (4th tone)
- 不 – bù (4th tone)
- 了 – liǎo (3rd tone in this word/meaning)

Tone sandhi rule for 不:

不 changes to bú (2nd tone) only before a 4th-tone syllable.
Example: 不是 búshì, 不要 búyào.

In 受不了 (shòu bù liǎo), liǎo is 3rd tone, not 4th, so 不 stays bù (4th tone).

So: shòu bù liǎo, not shòu bú liǎo.

Could I say 我今天太累了，所以受不了? Is that natural?

You can say 我今天太累了，所以受不了。, and it is grammatically correct:

所以 = “so / therefore”

However, in everyday speech, Chinese often:

leaves out connecting words like 所以 when the cause–effect relationship is obvious, and
simply uses a comma between the two clauses:
我今天太累了，受不了。
→ “I’m too tired today, (so) I can’t take it.”

So your version with 所以 is acceptable, but the original version without 所以 is actually more natural in casual conversation.

What’s the difference between 太累了, 很累, and 累死了?

All describe being tired, but with different strengths and styles:

很累 – hěn lèi
- “very tired” / “quite tired”
- Neutral, descriptive, not necessarily complaining.
太累了 – tài lèi le
- “too tired / so tired”
- Stronger, more emotional, often a complaint or feeling overwhelmed.
累死了 – lèi sǐ le
- Literally “tired to death”
- Very colloquial and strong, often exaggerated:
  “I’m exhausted / I’m dead tired.”

Your sentence:

我今天太累了，受不了。
Already sounds quite strong and emotional.
我今天累死了，受不了。 would be even more dramatic, almost like “I’m dead tired today, I just cannot take it at all.”