Paul est prudent ; en effet, il vérifie tout.

In French, when you describe someone with an adjective after être, you usually do not use an article.

So:

• Paul est prudent = Paul is careful/cautious

Not:

• Paul est un prudent ❌

That would sound unnatural in normal French.
French uses the bare adjective after être much like English does in Paul is careful.

Prudent means careful, cautious, or sensible.

Although English also has the word prudent, in everyday translation careful or cautious is often more natural.

So in this sentence, Paul est prudent suggests that Paul is the kind of person who checks things and avoids mistakes or risk.

Because the sentence is describing Paul, not describing how he does an action.

• prudent = adjective, describing a person
• prudemment = adverb, describing how someone does something

Here:

• Paul est prudent = Paul is cautious

If you used the adverb, it would need a verb:

• Paul agit prudemment = Paul acts cautiously

So prudent is correct because it describes Paul’s character or quality.

En effet means something like indeed, in fact, or as a matter of fact.

In this sentence, it introduces an explanation or confirmation of what came before:

• Paul est prudent ; en effet, il vérifie tout.

The second part supports the first:

• Paul is cautious;
• indeed / in fact, he checks everything.

So en effet is not just filler—it shows that the next clause is evidence for the previous statement.

The semicolon links two closely related ideas:

• Paul est prudent
• en effet, il vérifie tout

The second part explains the first one, so the semicolon works well.

You may also see:

• Paul est prudent. En effet, il vérifie tout.
• Paul est prudent, en effet, il vérifie tout. (less elegant in many contexts)

The semicolon is a neat way to connect two complete thoughts without fully separating them.

Because French normally requires an explicit subject pronoun with a conjugated verb.

So you say:

• il vérifie tout = he checks everything

Not:

• vérifie tout ❌

Unlike English, French cannot usually omit the subject in a normal statement.
Even though we already know the sentence is about Paul, French still needs il.

Vérifie is the 3rd person singular present tense of vérifier.

Conjugation:

• je vérifie
• tu vérifies
• il / elle vérifie
• nous vérifions
• vous vérifiez
• ils / elles vérifient

Since the subject is il (referring to Paul), French uses vérifie.

So:

• il vérifie tout = he checks everything / he verifies everything

Here, tout means everything.

So:

• il vérifie tout = he checks everything

It is tout because it is being used as a singular indefinite object meaning everything.

Compare:

• tout = everything
• tous = all / everyone / all of them, depending on context

Examples:

• Il mange tout. = He eats everything.
• Tous sont prêts. = Everyone is ready.
• Il connaît tous ses voisins. = He knows all his neighbors.

So tout is the correct form here.

Yes, it changes if the person described is feminine.

Here, Paul is masculine, so:

• Paul est prudent

If it were a woman:

• Marie est prudente

Many French adjectives agree in gender and number with the noun they describe.

So you could also have:

• Paul et Luc sont prudents
• Marie et Anne sont prudentes

Sometimes, but not always.

In French, vérifier very often means to check in everyday situations, which is broader than English verify.

So in this sentence:

• il vérifie tout

the most natural English idea is:

• he checks everything

If you translate it as he verifies everything, that is possible, but it sounds more formal or narrower in English.

They are related, but they do not work the same way.

• parce que = because
• en effet = indeed / in fact

With parce que, you directly introduce the reason:

• Paul est prudent parce qu’il vérifie tout.

With en effet, you first make a statement, then add supporting evidence:

• Paul est prudent ; en effet, il vérifie tout.

So:

• parce que directly links cause and statement
• en effet sounds more explanatory or argumentative

Both can work, but they create a slightly different tone.

Yes, it is in the present tense.

• est = is
• vérifie = checks

In French, the present tense can describe:

• a general truth
• a habit
• something happening now

Here, it most naturally describes a habit or characteristic:

• Paul is a cautious person;
• he checks everything.

So the sentence is probably about his usual behavior, not just one single moment.