Why This Structure Unlocks B2 Production

In B1, you learned dont as the elegant replacement for de + noun. But dont has a boundary — and hitting that boundary without knowing about lequel forces you into clunky repetitions or grammatical errors that immediately signal incomplete mastery.

The system of lequel / laquelle / lesquels / lesquelles — and their contracted forms with prepositions — is the tool that handles every relative clause dont cannot. It appears constantly in legal, administrative, journalistic, and academic texts. Mastering the dont vs lequel boundary makes your writing structurally airtight.

🦝 Remy says: "On the DELF B2 Production Écrite, complex sentences with prepositional relative clauses are one of the clearest signs of syntactic control. The rule is mechanical once you learn it: if your preposition is complex (two or more words — au cours de, à la fin de, au centre de), dont is blocked. Use duquel / de laquelle / desquels / desquelles. Write this rule on a card. It will never fail you."

Core Lesson

The Lequel System — Forms

Lequel agrees in gender and number with the noun it refers to (its antecedent):

	Masculin singulier	Féminin singulier	Masculin pluriel	Féminin pluriel
Base	lequel	laquelle	lesquels	lesquelles
avec de (→ du/de la...)	duquel	de laquelle	desquels	desquelles
avec à (→ au/à la...)	auquel	à laquelle	auxquels	auxquelles

The Core Rule: When Dont Works and When It Fails

DONT works when the relative pronoun directly follows the verb or a simple noun:

C'est l'entreprise dont je connais le directeur. — It's the company whose director I know. (je connais le directeur de l'entreprise → dont = de l'entreprise)
Le rapport dont les conclusions sont claires. — The report whose conclusions are clear.
C'est un auteur dont j'apprécie l'œuvre. — It is an author whose work I appreciate.

DONT fails when the de is buried inside a complex prepositional phrase — a phrase of two or more words where de is not the first word:

Complex preposition	Example with lequel
au cours de	La conférence au cours de laquelle* il a pris la parole.*
à la fin de	La réunion à la fin de laquelle* il a démissionné.*
au centre de	La table au centre de laquelle* se trouve une bougie.*
en marge de	Les discussions en marge desquelles* un accord a été conclu.*
à l'issue de	Le procès à l'issue duquel* il a été acquitté.*
à côté de	L'immeuble à côté duquel* je travaille.*
en face de	Le bâtiment en face duquel* se trouve le musée.*

The test: if you can say dont but the sentence requires inserting it mid-phrase (La réunion dont à la fin...) — you are blocked. Switch to duquel/de laquelle.

Lequel with Simple Prepositions (Non-de)

Lequel also replaces qui/que after simple prepositions like avec, par, sur, dans, pour, sans when referring to things (not people):

C'est le dossier sur lequel je travaille depuis deux semaines. — It is the file on which I have been working for two weeks.
L'outil avec lequel ils ont bâti leur modèle. — The tool with which they built their model.
Les fenêtres par lesquelles on aperçoit la mer. — The windows through which one can see the sea.

For people with simple prepositions, you can use qui or lequel — both are correct:

L'ami avec qui (or avec lequel) je travaille. — The friend with whom I work.

For things, only lequel is possible after a preposition:

L'outil avec lequel ❌ (NOT: avec qui) ils ont construit le modèle.

Animate vs Inanimate with Complex Prepositions

With people in complex prepositional structures, both de qui and duquel/de laquelle are acceptable:

Le collègue à côté de qui (or duquel) je me suis assis. — The colleague next to whom I sat.

With things, only duquel/de laquelle is possible.

B1 → B2 Upgrade Table

B1 Attempt	B2 Correction	Rule
La réunion dont à la fin il est parti. ❌	La réunion à la fin de laquelle* il est parti.* ✅	Complex prep blocks dont
Le projet dont au centre se trouve une idée innovante. ❌	Le projet au centre duquel* se trouve une idée innovante.* ✅	Complex prep blocks dont
C'est un dossier dont je travaille dessus. ❌	C'est un dossier sur lequel* je travaille.* ✅	dont cannot follow preposition
L'outil avec qui ils ont travaillé. ❌	L'outil avec lequel* ils ont travaillé.* ✅	Things take lequel after prepositions

🦝 Remy's Exam Strategy: "In DELF B2 reading comprehension, complex relative clauses with auquel, à laquelle, desquels are routine in journalistic texts. When you encounter them, immediately locate the antecedent (the noun before the clause) and the preposition. This two-step parse will give you the grammatical skeleton of the sentence. Students who skip this step misread the logical relationship and answer comprehension questions incorrectly. Two seconds of clause analysis saves the point."

🎯 Today's Challenge

Write a 3-sentence paragraph describing a formal event (a summit, a trial, a conference, a board meeting) using at least two relative pronouns from today's lesson — one with a complex prepositional phrase and one simple dont. The paragraph should read as if excerpted from a quality newspaper.

⭐ Key Takeaways

The dont/lequel boundary is mechanical: If the preposition relating the clause to the antecedent is a multi-word phrase (au cours de, à la fin de, en face de), dont is blocked and lequel with its inflected contracted form is required. Memorize five high-frequency complex prepositions and you will handle 90% of cases.
Gender and number agreement is non-negotiable: Lequel must match the gender and number of the antecedent noun. A gender error (au cours duquel for a feminine noun) is a hard grammatical mistake visible to any examiner.
DELF reading strategy: In comprehension texts, these complex relative constructions are embedded in long sentences. Parse them left to right: locate the antecedent, identify the preposition, find the main verb of the relative clause. This three-step parsing method prevents misreading the sentence's logical core.

Advanced Relative Pronouns — Lequel as Object of Preposition