Learn Hardcore Japanese: zyuubunna suimin wo toru you ni site iru uti ni, kaze wo hikinikuku narimasita. - As I tried to get enough sleep, I became less likely to catch a cold.

V-る + ようにする
→ “to make an effort to do ~ / to try to do ~ / to arrange so that ~”
V-る + ようにしている
→ “to habitually make an effort to do ~ / to make it your routine to ~”

So:

十分な睡眠を取るようにする
= “(I will) try to get enough sleep / make sure to get enough sleep” (a decision, rule, or intention)
十分な睡眠を取るようにしている
= “I make it a habit to get enough sleep / I’m consistently trying to get enough sleep”

In the sentence:

十分な睡眠を取るようにしているうちに、風邪を引きにくくなりました。
“As I kept making sure to get enough sleep, I came to not catch colds so easily.”

The している tells us it’s not just a one‑time effort, but an ongoing habit over a period of time.

What is the role of うちに here, and how is it different from things like ながら or 間に?

うちに (written 内に) here means “while / over the time that / as (something continues).”

Pattern:

V-ている + うちに、…
→ “while (you are) doing … / as … continues, (some change happens).”

So:

十分な睡眠を取るようにしているうちに、風邪を引きにくくなりました。
= “While I was (for some time) making sure to get enough sleep, I ended up not catching colds so easily.”

Nuances vs. similar expressions:

うちに
- Often used with a change that happens gradually or almost without you noticing.
- Implies “before I realized it / over time.”
間に (あいだに)
- Focuses on a time span during which something happens.
- Common with things like “while I was out, someone came,” etc.
- Less about gradual change, more about “within that interval”.
ながら
- Means “while doing A, (also) doing B at the same time.”
- Used for two concurrent actions done by the same subject.
- You wouldn’t say
  ✕ 睡眠を取るようにしながら、風邪を引きにくくなりました。
  because “becoming hard to catch a cold” is not a deliberate action you do while doing something else; it’s a result/change.

So うちに is natural here because it expresses:
“As I kept this habit up, over time, a change occurred (I stopped catching colds so easily).”

Why do we say 睡眠を取る? Does 取る really mean “take” here?

Yes, 取る (とる) literally means “to take,” but in Japanese it’s used in many set combinations that in English would more naturally be “get,” “have,” or “take,” depending on context.

睡眠を取る (すいみんをとる) means “to get (enough) sleep / to take sleep / to sleep sufficiently.”

Similar patterns:

休みを取る – to take a day off / take a break
メモを取る – to take notes
栄養を取る – to take in nutrition
連絡を取る – to get in touch (with someone)

So 十分な睡眠を取る = “to get sufficient sleep,” a standard and natural expression.

Why is it 十分な睡眠 and not something like 十分睡眠 or 十分の睡眠? What kind of word is 十分 here?

十分 (じゅうぶん) is a word that can function as:

a な-adjective: 十分な
an adverb: 十分に
a noun meaning “enough; plenty”

In 十分な睡眠, it’s used as a な-adjective modifying a noun:

十分な + Noun
→ 十分な睡眠 (enough sleep)
→ 十分な時間 (enough time)
→ 十分な準備 (enough preparation)

Why not 十分の睡眠?

X分のY is a very common pattern for fractions or ratios, like:
10分の1 = “one tenth”
So 十分の睡眠 strongly suggests something like “one‑tenth of sleep” or “ten out of (something) sleep,” which is not what we want.

Why not just 十分睡眠?

Japanese compounds sometimes drop particles (e.g., 日本語学校), but 十分睡眠 is not a natural fixed compound; native usage is 十分な睡眠.

So, 十分な睡眠 is the normal, grammatical way to say “sufficient sleep.”

Why does 風邪を引く mean “to catch a cold”? What is 引く doing here?

Literally, 引く (ひく) means “to pull,” but in Japanese there are many idiomatic uses where the meaning becomes more abstract or specialized. 風邪を引く is a fixed expression meaning “to catch a cold.”

You can think of it as “to pull in a cold (toward yourself),” but in practice it’s just an idiom you need to memorize as a chunk:

風邪を引く / かぜをひく – to catch a cold

Other examples of 引く in set phrases:

辞書を引く – to look something up in a dictionary
線を引く – to draw a line
注意を引く – to attract attention

In this sentence:

風邪を引きにくくなりました。
literally: “It became hard to catch a cold.”
Natural English: “I stopped catching colds so easily / I became less likely to catch colds.”

How does 引きにくくなりました work grammatically? What is にくく, and why do we use なりました?

Break it down:

Base verb: 引く – to catch (a cold, here)
Verb stem: 引き
Pattern: V-stem + にくい
→ “hard/difficult to do V,” or “not likely to do V”

So:

引きにくい = “hard to catch (a cold)” / “not easy to catch a cold”

～くなる with い-adjectives expresses “become ~”:

高い → 高くなる (to become expensive/tall)
寒い → 寒くなる (to become cold)
難しい → 難しくなる (to become difficult)

Since にくい is an い-adjective, its adverbial / 連用形 is にくく, so:

引きにくい → 引きにくくなる
“to become hard to catch (a cold)”

Then put なる in the past polite:

引きにくくなりました
“(it) became hard to catch (a cold)”

Natural translation:
“I became less likely to catch colds / I didn’t catch colds as easily anymore.”

Why is している present/progressive, while なりました is past? Is that a tense mismatch?

In Japanese, subordinate clauses often use the non‑past / progressive form even when the main clause is in the past. The tense of the whole sentence is anchored by the main verb, here なりました (past polite).

Structure:

十分な睡眠を取るようにしているうちに
“while (I was) in the state of making it a habit to get enough sleep”
風邪を引きにくくなりました
“(I) became less likely to catch colds.”

So the overall meaning is past:

“As I was keeping up the habit of getting enough sleep, I came to not catch colds so easily.”

Using していた instead (しているうちに → していたうちに) is possible in some contexts, but V-ているうちに is a set pattern for “while (something) is ongoing, a change happens,” so native speakers naturally choose しているうちに here, even though the whole story is about the past.

Who is actually becoming less likely to catch colds? There’s no 私 in the sentence—how do we know the subject?

Japanese often omits the subject when it is clear from context. In:

十分な睡眠を取るようにしているうちに、風邪を引きにくくなりました。

The person who 取る (gets sleep) and 風邪を引きにくくなりました (became less likely to catch colds) is understood to be the same person, usually the speaker.

So the implied full version would be:

（私は）十分な睡眠を取るようにしているうちに、（私は）風邪を引きにくくなりました。

In natural Japanese, repeating 私は is unnecessary and can sound heavy or unnatural if it’s obvious from context. Context (who’s talking, what was said before) tells you that it’s “I” who changed.

Could you express the same idea without うちに? For example, using から or ので instead?

Yes, you can express roughly the same idea with a more direct cause‑and‑effect structure:

十分な睡眠を取るようにしているから、風邪を引きにくくなりました。
十分な睡眠を取るようにしているので、風邪を引きにくくなりました。

Both mean:
“Because I’ve been making sure to get enough sleep, I’ve become less likely to catch colds.”

Nuance differences:

から / ので
- Explicitly mark reason/cause: “because ~, (therefore) …”.
- Very straightforward cause‑and‑effect.
うちに
- Focuses more on the process over time and the gradual/almost unnoticed change.
- Feels like: “As I kept doing X, before I knew it, Y (change) happened.”

So the original:

十分な睡眠を取るようにしているうちに、風邪を引きにくくなりました。

has a nuance of “Over time, as I continued that habit, I found that I just wasn’t catching colds so easily anymore,” rather than bluntly stating a cause.