Learn Hardcore Japanese: watasitati ha kaze ga tuyoi node, rensyuu wo tyuusisimasu. - Because the wind is strong, we will cancel practice.

は in 私たちは marks the topic: “as for us.”
が in 風が強い marks the grammatical subject of the adjective 強い: “the wind is strong.”
So the sentence is “As for us, because the wind is strong, [we] will cancel practice.”

Why is it 風が強い and not 風は強い?

With adjectives describing a state, especially natural phenomena, X が [adjective] is the neutral way to state “X is [adjective].”
Using 風は強い makes “wind” the topic and can sound contrastive or explanatory (“as for the wind, it’s strong”), which is possible but shifts the nuance.

Can I drop 私たち?

Yes. Subjects are often omitted when obvious. 風が強いので、練習を中止します。 is perfectly natural. In announcements, you’ll also see topicalization like 本日の練習は中止します or …は中止です.

Is ので the same as から? Which should I use?

Both mean “because.”

ので sounds more objective/soft and is common in announcements or polite speech.
から is a bit more direct/casual.
So in this context ので fits well. You could say 風が強いから、練習を中止します in casual speech.

Do I need to add な or です before ので?

After verbs and i-adjectives, use the plain form: 強いので, 行くので.
After nouns/na-adjectives, use なので: 学生なので, 静かなので.
Avoid 強いですので in learner Japanese; while you may hear it in ultra-polite speech, textbooks prefer the plain form before ので.

Why is the first clause plain (強い) but the second polite (中止します)?

It’s normal. Subordinate clauses (like the reason clause before ので) typically use the plain form, while the main clause sets the politeness. So “plain + ので, polite main clause” is standard.

Why use 中止します instead of やめます?

中止する means “to cancel” an event/activity—official-sounding and standard for schedules, events, practices, games.
やめる means “to stop/quit (doing something)” and is more personal/casual.
So for canceling practice, 練習を中止します is the appropriate formal choice.

What’s the nuance difference among 練習を中止します, 練習は中止します, and 練習は中止です?

練習を中止します: treats 練習 as the direct object of the action “cancel.”
練習は中止します: topicalizes practice—“As for practice, [we] will cancel it.” Slightly more announcement-like.
練習は中止です: purely states the status—“Practice is canceled.” Very common on notices.

Is 中止にします or 中止となります okay? How about 中止いたします?

中止にします: “we will make it canceled,” emphasizes a decision.
中止となります: impersonal/neutral “will become canceled,” common in announcements.
中止いたします: very polite/humble version of 中止します, used in formal announcements.

Do I always need します after 中止?

To make it a verb, yes: 中止する／中止します. As a noun predicate, you can say 中止です (“is canceled”). Both are common, depending on style.

Is this how it’s normally written (with spaces)?

No. Japanese normally doesn’t use spaces. The sentence would be:
私たちは風が強いので、練習を中止します。

How do you pronounce the sentence?

watashitachi wa kaze ga tsuyoi node, renshū o chūshi shimasu.
Notes: 練習 = renshū (ren-shoo), 中止 = chūshi (choo-shee). You may also see it romanized as “renshuu / chuushi.”

Can I say 風が強くて、練習を中止します?

Yes. 〜くて can express a cause, but it’s looser and more conversational. 〜ので sounds clearer and more neutral/formal about the reason.

Can I say 風が強いせいで、練習を中止します?

Yes, but せいで carries a negative/blame nuance (“due to/because of” with an unfavorable outcome). It subtly frames the wind as the “fault.” ので is more neutral.

How would I avoid mentioning who cancels it?

Use impersonal or status expressions:

練習は中止です。
練習は中止となります。
These are common on public notices and don’t specify an agent.

Are there more formal alternatives for “because of strong wind”?

Yes. Announcement style often uses:

強風のため、練習は中止します／中止です。
強風により、練習は中止となります。
These sound official and concise.