happyou no mae ha dokidokisita keredo, hanasihazimetara otituita.

発表の前 means before the presentation.

Here, 発表 is being treated like a noun, so の links it to 前:

• 発表 = presentation
• 前 = before / in front of
• 発表の前 = before the presentation

You may also see:

• 発表前 = pre-presentation / before the presentation
  This is more compact and feels a bit more like a set phrase.
• 発表する前 = before presenting / before I gave the presentation
  This focuses more on the action to present rather than the event as a noun.

So in this sentence, 発表の前 naturally means before the presentation as a time period.

The は marks 発表の前 as the topic:

• 発表の前は = as for before the presentation...

This gives the sentence a contrastive or frame-setting feeling. It sets up one time period, and then the rest of the sentence contrasts it with another:

• Before the presentation, I was nervous, but once I started talking, I calmed down.

So は helps divide the sentence into two stages:

1. 発表の前は → before the presentation
2. 話し始めたら → once I started speaking

どきどき is a Japanese sound-symbolic word that describes a pounding heart.

So どきどきした literally means something like:

• my heart was pounding
• I felt nervous
• I was anxious / excited

In this sentence, it most naturally means I was nervous.

Japanese often uses these mimetic or sound-symbolic words with する:

• どきどきする = to feel one’s heart pounding / to be nervous
• past form: どきどきした

So the structure is:

• どきどき
  • する
• どきどきした = felt nervous / got nervous

It is in the past tense because the sentence is describing how the speaker felt during a past event.

The speaker is looking back and saying:

• before the presentation, they were nervous
• after they started speaking, they calmed down

So both emotional states are reported as past experiences:

• どきどきした = was nervous
• 落ち着いた = calmed down

Even if English sometimes uses other wording, Japanese commonly uses past tense here because the whole situation is being narrated as something that already happened.

Here, けれど means but / although.

It connects two parts of the sentence:

• 発表の前はどきどきしたけれど、
• 話し始めたら落ち着いた。

So the idea is:

• I was nervous before the presentation, but once I started talking, I calmed down.

Why not でも?

• けれど joins two clauses more smoothly within one sentence.
• でも is often used more like but at the start of a new sentence or statement.

Compare:

• どきどきしたけれど、落ち着いた。
  Natural clause-linking.
• どきどきした。でも、落ち着いた。
  Also possible, but more broken into separate sentences.

So けれど is the more natural connector here.

けれど is fairly neutral and very common.

Related forms include:

• けど = more casual
• けれど = neutral
• けれども = slightly more formal or careful
• が = often used in more formal or written contexts as but

So this sentence sounds natural and standard. It is neither especially stiff nor especially casual.

話し始めたら breaks down like this:

• 話す = to speak
• 話し始める = to begin speaking
• 話し始めた = began speaking
• 話し始めたら = when / once / if I began speaking

There are actually two grammar points here:

1. Compound verb

   • 話す
     • 始める
   • 話し始める = to start speaking

2. たら conditional

   • 話し始めたら = when / once I started speaking

In this sentence, たら is not really an if in the hypothetical sense. It means more like:

• when I started talking
• once I started talking

That fits the real sequence of events.

That is just how the たら form is built.

You make it from the plain past form:

• 話し始める
• 話し始めた
• 話し始めたら

Even though it uses the past form, it does not always mean past time by itself. It creates a conditional or time-linked meaning such as:

• if
• when
• once
• after

In this sentence, because the action really happened, たら is best understood as:

• once I started speaking
• when I started speaking

So the past-looking form is part of the grammar pattern, not just a simple past tense marker.

落ち着く means to calm down, to settle down, or to become composed.

So:

• 落ち着いた = calmed down / became calm

In this sentence, it means the speaker stopped feeling so nervous after beginning to talk.

A useful nuance:

• 落ち着いた often suggests not just a change in emotion, but becoming more settled, composed, or mentally steady.

So this is a very natural verb here.

The subject is omitted, which is very normal in Japanese.

From context, the subject is understood to be the speaker:

• I was nervous before the presentation, but once I started talking, I calmed down.

Japanese often leaves out subjects when they are obvious. Since the sentence describes personal feelings and actions in sequence, a listener naturally understands that the speaker is talking about themselves.

So there is no need to say 私は unless the speaker wants extra emphasis or contrast.

Yes, definitely.

• 緊張した = was nervous / felt tense
• どきどきした = felt my heart pounding / was nervous

The difference is nuance:

• 緊張した is more direct and straightforward: I was nervous
• どきどきした is more vivid and emotional: my heart was pounding

So どきどきした sounds a little more expressive and personal.

For example:

• 発表の前は緊張した。
  I was nervous before the presentation.
• 発表の前はどきどきした。
  My heart was pounding before the presentation.

Both are natural, but the one in your sentence paints the feeling more vividly.

Most likely, yes.

発表 can mean several kinds of presentation or announcement, depending on context. But because the sentence says:

• 話し始めたら = once I started speaking

it strongly suggests an oral presentation in front of other people, such as:

• a class presentation
• a work presentation
• a speech-like report

So in this context, presentation is the most natural interpretation.

The sentence is built in two contrasting parts:

• 発表の前はどきどきしたけれど、
• 話し始めたら落ち着いた。

A natural structure breakdown is:

1. 発表の前は
   As for before the presentation...

2. どきどきした
   I was nervous / my heart was pounding

3. けれど
   but

4. 話し始めたら
   once I started speaking

5. 落ち着いた
   I calmed down

So the whole sentence contrasts:

• before speaking → nervous
• after starting → calm

That contrast is one of the main things the grammar is showing.