Learn Hardcore Chinese: wèile tígāo zhōngwén shuǐpíng, wǒ měitiān dōu zài sùshè rènzhēn xuéxí. - In order to improve my Chinese level, I study diligently in the dorm every day.

This 了 is not the aspect particle that marks completion or change.
You cannot usually split it or remove it and keep the same meaning:
- 为了提高中文水平 ✅
- 为提高中文水平 ✅ (more formal/literary, but still ok)
- 为提高中文水平了 ❌
Think of 为了 as one unit: a purpose marker.

When you see 为了 + verb/noun phrase, just read it as in order to ...

What is the exact meaning of 提高, and why use it with 水平?

提高 means to raise / to improve / to increase (the level or quality of something).

It often collocates with 水平 (level), 能力 (ability), 成绩 (grades), 效率 (efficiency), etc.
提高中文水平 literally = raise/improve (my) Chinese level → improve my Chinese.

Contrast with:

学中文 = learn/study Chinese (general learning)
进步 (as a verb) = to make progress
- 我的中文进步了。 = My Chinese has improved.
提高中文水平 emphasizes actively working to improve the level, often through effort or study.

What does 中文水平 actually mean? Is 水平 just “level”?

Yes, 水平 means level / standard / proficiency.

中文水平 = Chinese (language) proficiency / level of Chinese
Unlike English, Chinese often uses a word like 水平 with a field:
- 英语水平 = English level
- 口语水平 = speaking level
- 写作水平 = writing level

Grammatically, 中文水平 is a noun phrase (Chinese + level) and is the object of 提高.

Why is 都 used with 我每天? I thought 都 meant “all”.

都 most basically means all, but it appears in several common patterns, including with 每 (every).

In 我每天都在宿舍认真学习:

每天都 is a very common collocation: every day (without exception).
都 emphasizes regularity / no exceptions:
- 我每天在宿舍学习。 = I study in the dorm every day.
- 我每天都在宿舍学习。 = I study in the dorm every single day (stronger).

You will often see:

每个人都喜欢… = Everyone likes …
每次都迟到。 = (He) is late every time.

So here 都 functions as an intensifier with 每天, not as a plural marker for 我.

What is the role of 在 before 宿舍?

在 marks location (also sometimes time).

Pattern: 在 + place + verb phrase
- 在宿舍认真学习 = study seriously in the dorm.
In the full sentence:
- 我每天都在宿舍认真学习。
  Subject: 我
  Time: 每天都
  Location: 在宿舍
  Manner + verb: 认真学习

Without 在, 宿舍 alone would sound like a noun with no clear function in this sentence.

Why is it 在宿舍认真学习 and not 认真在宿舍学习?

Both could be understood, but the natural order follows a typical Chinese pattern:

Subject + Time + Location + Manner + Verb + Object

So:

我（subject）每天都（time）在宿舍（location）认真（manner）学习（verb）。

Putting 认真 right before 学习 keeps the modifier close to the verb it describes.
认真在宿舍学习 is not wrong grammatically, but it sounds less natural and slightly awkward. Most native speakers would prefer 在宿舍认真学习.

Is 认真 an adverb or an adjective here? What does 认真学习 really mean?

Here 认真 functions adverbially, modifying 学习.

认真 literally: serious, earnest, conscientious.
认真学习 ≈ study seriously / study hard / study carefully and attentively.

认真 can be:

Adjective: 他很认真。 = He is very serious/conscientious.
Adverb (no extra ending needed): 他认真工作。 = He works seriously/conscientiously.

Chinese often uses adjectives directly before verbs as adverbs; you do not need -ly or a special adverb ending.

What is the difference between 学 and 学习? Could this sentence use 学 instead?

学 and 学习 are closely related.

学 = to learn, to study (more basic, shorter)
学习 = to study, to learn (slightly more formal or neutral; can also be a noun in some contexts)

In most everyday contexts:

学中文 and 学习中文 both work.
学 is often used in speech; 学习 is very common in written or neutral/register speech.

In your sentence:

我每天都在宿舍认真学习。 ✅
我每天都在宿舍认真学。 ✅ (more colloquial, but understandable)

Using 学习 feels very natural in this more neutral, textbook-like sentence.

Why is there no 了 at the end of the sentence if I do this every day? How is tense shown?

Mandarin does not mark tense the same way English does. It often relies on:

Time words: 昨天, 现在, 明天, 每天, etc.
Aspect particles: 了, 过, 着 to show completion, experience, ongoing state.

Here:

每天 already tells us this is a habitual / repeated action.
Habitual actions usually do not take 了.
- 我每天都在宿舍认真学习。 = I study in the dorm seriously every day. ✅
- 我昨天在宿舍认真学习了。 = I studied seriously in the dorm yesterday. ✅ (completed event, so 了 is natural)

So the absence of 了 is exactly what we expect for a general routine.

Why is it just 宿舍 and not 宿舍里 or 在我的宿舍里?

All of these are possible, but with slightly different nuance:

在宿舍学习 = study in the dorm (general dorm location; very normal)
在宿舍里学习 = study inside the dorm (slightly more specific, but often similar in meaning)
在我的宿舍学习 = in my dorm room (emphasis that it is my dorm)
在我的宿舍里学习 = specifically inside my own dorm room

In many everyday contexts, 宿舍 alone is enough; 里 is optional when the location is naturally an enclosed space, and 我的 is not needed unless you want to contrast with someone else’s dorm.

Could we drop 每天, 都, or 在宿舍, and what would change?

Yes, you can drop some elements; the core grammar still works.

Drop 每天:
- 为了提高中文水平，我都在宿舍认真学习。
  Sounds a bit odd; 都 works best with something plural or repetitive (每天/每次/大家). You would normally also drop 都:
- 为了提高中文水平，我在宿舍认真学习。
  → I study in the dorm seriously (no explicit frequency).
Drop 都:
- 为了提高中文水平，我每天在宿舍认真学习。
  → Still means every day, but with slightly less emphasis on without exception.
Drop 在宿舍:
- 为了提高中文水平，我每天都认真学习。
  → Same idea, but no mention of location; just I study seriously every day.

So you can adjust these parts to focus on time, location, or frequency as you like.

Is 为 always pronounced wèi? Sometimes I see wéi.

The character 为 has two common pronunciations with different main uses:

wèi:
- Meaning: for, for the sake of
- In your sentence: 为了 (wèi le) = in order to
- Other examples:
  - 为了孩子 = for the children
  - 为你加油 = cheer for you
wéi:
- Meaning: to be / to act as / to do
- Common in more formal or set phrases:
  - 认为 = to think, to consider
  - 作为 = as, in the capacity of
  - 以为 = to think (often mistakenly)

In 为了, it is always pronounced wèi.