Pourtant introduces a concession. The first idea creates an expectation, then the second shows that reality did not follow this expectation. One can say, for example, Il était tard, pourtant la rue était encore animée. Time advancing would have made one expect calm, but the street remains lively. Pourtant thus adds a logical surprise, without cancelling the first information. It often appears after a pause or at the beginning of the second clause, especially in a narrative or explanatory style. In a sentence like Je l’ai appelé plusieurs fois. Pourtant, il n’a pas répondu, the second part presents a fact contrary to what was expected. The nuance is different from that of [Conjonctions causales], which explain the cause of a fact; here, the emphasis is on the gap between expectation and reality.

Direct contrast with mais

Usage	Explanation
Simple opposition	We use mais to show an immediate contrast between two ideas.
Soft correction	We also use mais to correct an idea without creating tension.
Spontaneous response	In conversation, mais is often used to react quickly to a remark.

Cependant is used to restrict an idea without directly contradicting it. The first proposition remains true, but the second specifies that it has limits or does not hold in all cases. In Le trajet est court, cependant il faut prendre deux correspondances, the brevity of the journey does not erase the difficulty of travel. Cependant is often suitable in a formal register, in writing as well as in prepared speech. It can appear at the start of the second sentence or after a main clause separated by a comma. It marks a milder reserve than mais in many contexts. It is often used with general ideas, findings, or reasoning. It also works in sentences close to those built with [Conjonctions de Subordination], when one idea frames or limits another.

Marked concession with pourtant

Usage	Explanation
Surprising result	We use pourtant when the result is contrary to what was expected.
Idea that lasts despite everything	Pourtant allows saying that information remains true despite a difficulty.
Expressive tone	In speech, pourtant often gives a livelier and stronger effect.

Adversative forms are not limited to a single word. Some are simple conjunctions like mais or or. Others are phrases like en revanche, au contraire, malgré cela, néanmoins, tout de même. They connect two ideas by showing an opposition, a correction or a reservation. Or often introduces a fact that changes the reasoning: Je pensais qu’il était absent, or il était déjà là. En revanche is used to oppose two elements in an organized contrast: Le premier exercice est facile, en revanche le second demande plus de temps. Au contraire strengthens the opposition by clearly reversing the first idea. Néanmoins and malgré cela retain a concession value close to cependant. The [Conjonctions corrélatives] also organize the relation between two ideas, but with a two-part structure more visible.

Restrictive nuance with however

Usage	Explanation
Limit of an assertion	We use cependant to say that an idea is true with a significant reservation.
Formal style	Cependant fits well in a more polished style, especially in writing.
Nuanced transition	We use cependant to link two sentences with a calm and precise transition.

An adversative connector links two units that must remain clearly separate. When it joins two clauses in the same sentence, it sits between them: Je voulais partir, mais il a commencé à pleuvoir. When it opens the second clause, it often comes after a strong pause: Je voulais partir. Pourtant, il a commencé à pleuvoir. In this case, punctuation helps show the change in direction. Some locutions place themselves more freely at the start of the new clause: Cependant, nous avons continué ; En revanche, elle a accepté. Others require a fixed place in the middle of the sentence: Il est malade, mais il travaille. When the connector only modifies a group of words, it stays close to that group: un costume simple mais élégant. The link must always appear exactly at the point where the opposition begins.

Main adversative forms

Idea
Mais is a simple conjunction very common in speech and writing.
Pourtant expresses a concession and emphasizes a surprise or a strong contrast.
Cependant is a more formal locution that marks a reservation or a limit.
Néanmoins brings a concession close to cependant with a more formal tone.

The choice of the connector depends on the context. In casual conversation, mais dominates. It is direct, clear and natural. Pourtant is suitable when you want to convey a surprise or a contrast with an expectation. Cependant and néanmoins belong more often to a formal register, especially in writing, in an article, an assignment or a presentation. En revanche works well when comparing two distinct realities. Au contraire is used to correct a previous idea outright. In a simple message, Je suis fatigué, mais je viens sounds natural. In a more formal reply, Le dossier est complet ; cependant, il manque une signature seems more appropriate. The meaning remains similar, but the tone changes. The same contrast can therefore be expressed with different forms depending on the level of language and the situation.

Placement of connectors in the sentence

Idea
Mais often sits between two clauses to mark the contrast.
Cependant often sits at the beginning of the second clause or after a comma.
Pourtant can open the sentence to emphasize the contrast.
A locution adversative should clearly connect two ideas without breaking fluency.

The choice of the connector depends on the context. In an ordinary conversation, mais dominates. It is direct, clear and natural. Pourtant is suitable when one wants to convey surprise or a contrast with an expectation. Cependant and néanmoins belong more often to a formal register, especially in writing, in an article, an assignment or a presentation. En revanche serves well when comparing two distinct realities. Au contraire is appropriate for frankly correcting a previous idea. In a simple message, I am tired, but I am coming sounds natural. In a more formal reply, The file is complete; however, it lacks a signature seems more suitable. The meaning remains close, but the tone changes. The same contrast can therefore be expressed with different forms depending on the level of language and the situation.

Choice of adversative register

Usage	Explanation
Colloquial language	We choose mais when we want a form simple and natural in everyday life.
Formal writing	We prefer cependant or néanmoins in a more formal or more thoughtful text.
Expressive effect	We use pourtant when we want to give more emphasis to the opposition.