Conjonctions d'Opposition

Oppositional conjunctions set two ideas in contrast: I wanted to go, *but I couldn't. He's tall, whereas his brother is short. The food was good; on the other hand, the service was slow. This family differs from the concessive family (*although, despite) in a subtle but important way. Concessive clauses acknowledge an obstacle and proceed anyway — they signal that the speaker has weighed a counterargument. Oppositional clauses simply juxtapose two things as different or contrary, without implying that one obstructs the other.

Because oppositional clauses present two facts standing side by side, they all take the indicative. This makes the family grammatically simpler than the concessive one — there is no subjunctive trap. The challenge instead is choosing the right marker for the right kind of contrast, and watching out for one classic English-speaker mistake with tandis que.

This page covers the main oppositional markers — mais, tandis que, alors que, par contre, en revanche, and au lieu de — and explains where each one fits.

mais — but (the universal)

Mais is the all-purpose contrast word, used at every register from texting to academic writing. It is a coordinating conjunction, meaning it links two independent ideas without subordinating either one.

Mais can also be used emphatically, as a kind of intensifier — mais oui! (why yes!), mais non! (of course not!), mais qu'est-ce que tu fais? (what on earth are you doing?). This is a hallmark of natural spoken French.

This emphatic mais has nothing to do with contrast — it is a separate function of the same word. Learners often miss it because their textbook only introduces mais as but.

tandis que / alors que — whereas, while (comparative contrast)

Tandis que and alors que both introduce a comparative contrast — they juxtapose two situations and invite the listener to notice the difference between them. The English equivalent is whereas or contrastive while. Both take the indicative.

The two conjunctions are nearly interchangeable, with one nuance: alors que can carry a slight tone of indignation or surprise — and yet, of all things — whereas tandis que tends to be more neutral, even slightly literary.

In this last example, alors que almost means and yet, with a clear edge of reproach. Swap it for tandis que and the indignation softens to a flat comparison.

Watch out: alors que can also mean "while" (temporal)

Here is the trap. Alors que has a second, temporal meaning: at the moment when, while X was happening. The contrast use and the temporal use sit in the same word, distinguished by context.

The temporal use is more common in narrative writing; the contrastive use dominates in argumentative and conversational French. Tandis que has the same two uses but leans more temporal in older writing and more contrastive in modern usage. Context usually makes the meaning clear, but be aware of the ambiguity when you read.

par contre — on the other hand (everyday)

Par contre introduces a contrast as a separate sentence or after a strong pause. It is the natural choice in conversation and most writing for setting up on the other hand. It is not a subordinating conjunction — it sits at the start of a new clause or sentence as a discourse connector.

For decades, prescriptive grammarians condemned par contre as an Anglicism and recommended en revanche instead. That battle is now lost in everyday French — par contre is fully accepted in speech and journalism, and most modern dictionaries list it without warning. In very formal writing (academic essays, official documents), some authors still prefer en revanche, but in normal contexts the two are functionally equivalent.

en revanche — on the other hand (formal)

En revanche is the elevated synonym of par contre. Same meaning, same grammar (discourse connector at the start of a clause), but a notably higher register. Use it in essays, formal reports, and careful speech.

A historical note: revanche originally meant revenge or return-blow, and the connector preserves that flavor — en revanche implies a kind of balancing counterweight, an exchange. Par contre is flatter, just against this, on the contrary.

au lieu de + infinitive — instead of (substitution)

Au lieu de + infinitive introduces a substitutive opposition — not just any contrast, but specifically the idea that one thing happened instead of another. This is structurally different from the other markers in this page: it takes an infinitive (or a noun), not a clause.

The infinitive after au lieu de refers to the same subject as the main verb. If you want to express instead of with a different subject in the second clause, French uses au lieu que + subjunctive — but this construction is rare, somewhat literary, and most speakers reach for a paraphrase instead.

In normal usage, au lieu de + infinitive dominates, and the same-subject constraint is almost always met because the speaker is contrasting two possible actions of the same person.

Au lieu de + noun is also possible:

Position and rhythm

Each of these connectors has a preferred position in the sentence:

• mais sits between the two contrasted clauses, with a comma before: X, mais Y.
• tandis que and alors que introduce the second (subordinate) clause: X, tandis que Y.
• par contre and en revanche typically open a new sentence or follow a strong pause: X. Par contre, Y or X ; par contre, Y.
• au lieu de
  • infinitive can open the sentence or come second: Au lieu de Y, X or X au lieu de Y.

Both word orders are natural; fronting the au lieu de phrase puts more emphasis on the alternative that was rejected.

Choosing between oppositional markers

Opposition vs concession — knowing the difference

This is the conceptual distinction that the whole oppositional family rests on. Compare:

The concessive version implies that the brother's meat-eating might somehow be relevant to the sister's vegetarianism — perhaps the speaker is explaining why family meals are awkward. The oppositional version just points out the difference between them, as a flat fact, with no implied causal tension. This is why concessive clauses take the subjunctive (the obstacle is being weighed) and oppositional clauses take the indicative (the two facts are simply placed side by side).

If you find yourself wanting to express X is true, but Y still holds despite that, you want a concessive (bien que, même si). If you just want to set X and Y in contrast, you want an oppositional (mais, tandis que, par contre).

Common Mistakes

The most common error English speakers make once they have learned about the subjunctive: overgeneralizing. Bien que takes the subjunctive, so they assume tandis que and alors que do too. They don't. Opposition is fact, and fact is indicative.

Par contre is a discourse connector, not a coordinating conjunction. Putting it after a comma in place of mais is the sort of thing that sounds slightly off to a native speaker — workable, but stylistically clumsy. Use a period or semicolon before par contre, or pick mais instead.

When the subjects match, French requires au lieu de + infinitive. The au lieu que + subjunctive form exists for different-subject cases but is uncommon and somewhat formal; most speakers paraphrase.

For pure temporal while, pendant que is the cleanest choice — it has no contrastive reading. Alors que and tandis que can mean while temporally, but they invite the listener to also hear a possible contrast.

Match the connector to the register of the surrounding language. En revanche belongs in essays and formal writing; par contre belongs everywhere else.

Key takeaways

Oppositional conjunctions juxtapose two facts as contrasts — they all take the indicative because they are not weighing one fact against another, just placing them side by side. The hardest part of this family is choosing the right marker: mais is the universal but; tandis que and alors que are whereas (with alors que sometimes adding a hint of reproach, and both potentially temporal); par contre and en revanche are sentence-opening on the other hand (the first everyday, the second formal); au lieu de + infinitive is instead of with same-subject contrast. Watch for the temporal-vs-contrastive ambiguity in alors que and tandis que, and remember that par contre prefers to open a new sentence rather than fill the slot of mais.