asa okita bakaride bonyarisite ite, akubi mo nakanaka tomaranakatta.

Because 朝 is a time word, and time words in Japanese often appear without a particle.

So:

• 朝起きた = woke up in the morning
• 朝に起きた is generally not how this would be said

This is similar to other time expressions like:

• 今日行く = go today
• 昨日帰った = went home yesterday
• 朝食べた = ate in the morning

So 朝 is simply setting the time for 起きた.

Because V-ta + ばかり means just did V.

So:

• 起きたばかり = just woke up

By contrast, V-te ばかりいる / V-te ばかり has a completely different meaning: do nothing but V or keep V-ing.

For example:

• 遊んでばかりいる = he does nothing but play

So in this sentence, 起きたばかり is the correct pattern because the speaker means they had only just woken up.

Here, ばかりで means something like:

• having just...
• because I had just...
• since I had just...

So:

• 朝起きたばかりで = having just woken up in the morning / because I had just woken up

The ばかり part means just did, and the で connects that clause to what follows.

In this sentence, the nuance is not just sequence, but also background/cause:

• I had just woken up,
• so I was groggy,
• and my yawning would not stop.

ぼんやりする means to be absent-minded, spaced out, dazed, groggy.

So:

• ぼんやりしていて = being groggy / dazed, and...

In this sentence, it describes the speaker’s condition after just waking up.

A natural English sense would be:

• I was still groggy
• I was in a dazed state

Because this is after waking up, groggy is probably the most natural interpretation.

This comes from ぼんやりしている.

Breakdown:

• ぼんやりする = to be dazed / to zone out
• ぼんやりしている = to be in that state
• ぼんやりしていて = the -te form used to connect to the next clause

So していて is not two separate ideas being stacked randomly. It is just the connected form of している.

In other words:

• ぼんやりしていて、あくびも...
  = being groggy, and my yawns also...

This -te connection links the state to the next part of the sentence.

ぼんやり is a mimetic/onomatopoeic-style word often used adverbially, and it commonly appears with する:

• ぼんやりする = to be vague/dazed/spaced out

So in practice, learners often treat it as part of the set expression ぼんやりする.

You may also see it used adverbially:

• ぼんやり見る = look vacantly
• ぼんやり考える = think vaguely

In this sentence, it is part of ぼんやりしていて, from ぼんやりする.

Here, も means also or even.

So:

• あくびも止まらなかった = even my yawning wouldn’t stop / my yawns wouldn’t stop either

It adds the idea that, in addition to being groggy, the yawning was also a problem.

So the sentence has a kind of piling-up effect:

• I had just woken up,
• I was groggy,
• and even the yawning wouldn’t stop.

With a negative verb, なかなか usually means:

• not easily
• not readily
• not for a while

So:

• なかなか止まらなかった = didn’t stop easily / wouldn’t stop for quite a while

This is very important, because なかなか changes depending on whether the verb is positive or negative.

For example:

• なかなかいい = quite good / pretty good
• なかなか止まらない = doesn’t stop easily

Here, because 止まらなかった is negative past, the meaning is wouldn’t stop rather than quite stopped or anything like that.

Because 止まる is intransitive: to stop.

Here, あくび is the thing that would not stop:

• あくびが止まらない = the yawning won’t stop

If the sentence used 止める, that would be transitive: to stop something.

• 止められなかった = couldn’t stop it

That would focus more on the speaker’s inability to stop the yawning.

But 止まらなかった focuses on the yawning itself:

• the yawns just wouldn’t stop

That is very natural in Japanese.

It has both, but there is definitely a cause-and-effect nuance.

Structure:

• 朝起きたばかりで = having just woken up / because I had just woken up
• ぼんやりしていて = I was groggy
• あくびもなかなか止まらなかった = and my yawns wouldn’t stop easily

So it is not just a neutral list. The first part sets up the reason/background for the later parts.

A natural flow is:

• Since I had just woken up, I was groggy, and my yawning wouldn’t stop.

The subject is omitted because Japanese often leaves it out when it is obvious from context.

The most likely subject is:

• I

So the full sense is something like:

• I had just woken up that morning, was groggy, and my yawns wouldn’t stop.

Japanese does this constantly. If the speaker is talking about their own experience, 私 is usually unnecessary.

Because in Japanese, when clauses are connected with -te or similar linking forms, the earlier parts often do not need their own final tense marking.

Here:

• 起きた already has past marking because it is part of 起きたばかり
• ぼんやりしていて is a connected clause
• 止まらなかった is the final predicate, so it carries the main sentence-ending tense

This is very normal Japanese sentence structure. The earlier clauses set up the situation, and the final verb completes the sentence in the past.

So the whole sentence is understood as a past situation, even though only the last clause ends with a full sentence-final past form.