J’ai chaud, donc Paul ouvre la porte.

In French, feelings like hot, cold, hungry, and thirsty are often expressed with avoir (to have), not être (to be).

So French says:

• j’ai chaud = literally I have heat
• j’ai froid = I am cold
• j’ai faim = I am hungry
• j’ai soif = I am thirsty

A learner should be careful with je suis chaud. In many contexts, that does not mean I’m hot in the normal temperature sense. It can sound odd or suggest something else depending on context. For body temperature or feeling warm, j’ai chaud is the normal expression.

Because French usually avoids a clash between two vowel sounds. When je comes before a verb starting with a vowel, the e drops and becomes an apostrophe.

So:

• je + ai → j’ai
• je + aime → j’aime
• je + habite → j’habite

This is called elision.

Here, ai is the present tense of avoir.

The verb avoir in the present tense is:

• j’ai
• tu as
• il / elle / on a
• nous avons
• vous avez
• ils / elles ont

So j’ai chaud is present tense: I am hot / I feel hot.

Donc means so, therefore, or thus.

In this sentence, it links the first idea to the result:

• J’ai chaud = I’m hot
• donc = so / therefore
• Paul ouvre la porte = Paul opens the door

So donc shows consequence: because the speaker is hot, Paul opens the door.

Yes, sometimes. Donc is fairly flexible, although some positions sound more natural than others.

For example:

• J’ai chaud, donc Paul ouvre la porte.
• J’ai chaud. Paul ouvre donc la porte.

Both are possible, but the emphasis changes a little.

• When donc comes between the two clauses, it clearly means so / therefore.
• When it appears inside the second clause, it can sound a bit more formal or slightly more emphatic.

For a learner, the version in your sentence is very straightforward and natural.

Ouvre is the third person singular present tense of ouvrir (to open), because the subject is Paul.

Present tense of ouvrir:

• j’ouvre
• tu ouvres
• il / elle / on ouvre
• nous ouvrons
• vous ouvrez
• ils / elles ouvrent

Since Paul = he, French uses the il/elle/on form:

• Paul ouvre la porte.

Because Paul is already the subject.

French normally uses either:

• a noun subject: Paul ouvre la porte
• or a subject pronoun: Il ouvre la porte

Using both together, like Paul il ouvre la porte, can happen in spoken French for emphasis or informality, but it is not the neutral standard form here.

So the normal sentence is simply:

• Paul ouvre la porte.

La porte means the door, while une porte means a door.

French often uses the definite article when the door is specific or obvious from the situation, such as the door of the room everyone is in.

So:

• Paul ouvre la porte = Paul opens the door
• Paul ouvre une porte = Paul opens a door

In your sentence, la porte suggests a particular door that both speaker and listener can identify.

A simple pronunciation guide is:

zhay show, donk Pol oovr la port

A few notes:

• j’ sounds like the s in measure
• ai in j’ai sounds roughly like ay
• chaud sounds like show
• Paul sounds like Pol
• ouvre is roughly oovr
• the final e in porte is not pronounced

Depending on accent and speed, the pronunciation may vary a little.

Yes. The French present tense often covers both the English simple present and present progressive, depending on context.

So Paul ouvre la porte can mean:

• Paul opens the door
• Paul is opening the door

In a sentence like this, English often chooses the form that sounds most natural in context. French does not always make that distinction.

Not with exactly the same meaning.

• donc means so / therefore and introduces a result
• parce que and car mean because, and introduce a cause

Your sentence is:

• J’ai chaud, donc Paul ouvre la porte.
• I’m hot, so Paul opens the door.

If you use parce que, you would change the relationship:

• Paul ouvre la porte parce que j’ai chaud. = Paul opens the door because I’m hot.

That is a correct sentence, but it is structured differently. So donc and parce que / car are not interchangeable word-for-word.

The word order is quite standard:

• J’ai chaud = subject + verb + adjective
• donc = linking word
• Paul ouvre la porte = subject + verb + object

French often follows a straightforward subject + verb + object pattern in statements. So this sentence is a good example of normal French word order.

Yes, if it is already clear who he is.

Then you would say:

• J’ai chaud, donc il ouvre la porte.

That means:

• I’m hot, so he opens the door.

Use Paul when you want to name the person directly; use il when the reference is already known from context.