tumari, asita ha hima desu.

つまり means in other words, that is to say, or so. It is used to sum up or restate something that came before.

So つまり、明日は暇です。 feels like the speaker is concluding something from earlier context, such as:

• So, tomorrow I'm free.
• In other words, tomorrow is open.

If you say this sentence by itself, つまり can sound a little abrupt, because it usually refers back to a previous explanation.

Here, は marks 明日 as the topic: as for tomorrow.

So the structure is roughly:

• 明日 = tomorrow
• は = topic marker
• 暇です = is free / is not busy

A natural way to think of it is:

As for tomorrow, [someone] is free.

This is very common in Japanese. Time expressions are often introduced as the topic of the sentence.

Words like 今日, 明日, and 昨日 usually do not need に when they are used as time expressions.

So:

• 明日は暇です = natural
• 明日暇です = also natural
• 明日に暇です = unnatural here

Japanese often uses に with more specific time expressions, such as:

• 3時に
• 月曜日に
• 7月1日に

But with everyday words like 明日, 今日, and 昨日, に is often omitted.

Japanese often leaves out the subject when it is clear from context.

So 明日は暇です could mean:

• I'm free tomorrow.
• You're free tomorrow.
• We're free tomorrow.

The listener figures out the subject from the conversation.

This is one of the biggest differences from English: Japanese does not need to state the subject every time if everyone already knows who is being talked about.

暇 means free, not busy, or having spare time.

Grammatically, it behaves like a na-adjective (also called an adjectival noun). That is why you can say:

• 暇です = polite
• 暇だ = plain
• 暇な人 = a free person / a person who has free time

You cannot treat it like an i-adjective, so 暇い is wrong.

Yes. 暇 means more than just available in a neutral schedule sense. It often suggests having free time or not being busy.

Depending on the situation, it can sound:

• perfectly normal
• a little blunt
• like having nothing to do

For example, asking someone 明日暇ですか。 is common, but in some situations 明日空いていますか。 may sound a little softer or more polite, especially when talking about schedule availability.

So 暇 is correct here, but its nuance is slightly more personal than a purely calendar-based available.

Both can be translated as free or available, but they are not exactly the same.

• 暇です = I have free time / I'm not busy
• 空いています = my schedule is open / I am available

For a person, both can work. But:

• 暇 can sound more like I have nothing going on
• 空いている can sound more like there is an opening in my schedule

So in many practical situations:

• 明日は暇です。 = I'm free tomorrow.
• 明日は空いています。 = I'm available tomorrow.

The second one is often a bit more neutral in business or scheduling contexts.

Usually, は is the natural choice.

• 明日は暇です。 = As for tomorrow, [someone] is free.

If you say 明日が暇です, it sounds more specific or contrastive, as if you are identifying tomorrow as the free day:

• The day that is free is tomorrow.

So が is not impossible, but it is not the default here. For a simple statement, は is better.

Because 暇 itself already expresses the idea of free time / being free.

So Japanese says:

• 暇です = is free / has free time

You do not normally say 暇があります to mean I am free.

If you want to say I have time, you could say something like:

• 時間があります = I have time

But for I’m free, 暇です is the natural expression.

In casual speech, you could say:

• つまり、明日は暇だ。
• つまり、明日暇。

The second one is very casual and conversational.

So the polite/formal level in your sentence comes mainly from です.

In this sentence, the most natural reading is ashita.

So the sentence would normally be read:

つまり、あしたはひまです。

Other readings of 明日 exist, such as asu and myōnichi, but:

• ashita = most common in everyday conversation
• asu = a bit more formal
• myōnichi = quite formal or stiff in normal conversation

No. Standard Japanese is normally written without spaces:

つまり、明日は暇です。

The spaces are often added in textbooks or learning materials to make the structure easier to see. The comma after つまり is normal, though, because つまり is often separated as a discourse marker.