Concours ENS Yaoundé common mistakes
Concours ENS Yaoundé · Understand the traps and how to avoid them.
In Culture générale, candidates answer the essay prompt with a memorised, pre-packaged dissertation plan (e.g. a stock « thèse/antithèse/synthèse » on a theme like « la science et la société ») instead of addressing the exact wording of the sujet, and recycle examples from a manual without linking them to the question asked.
The épreuve is a timed 4–5 hour essay under heavy pressure; candidates prepare by memorising model plans and citations, and in the exam room they default to the rehearsed structure because it feels safe. Many also misread the sujet by skipping the analysis of its key terms (e.g. confusing « progrès » with « technique »), so the recycled plan appears to fit.
What to do instead
In the first 10 minutes, write out an explicit reformulation of the sujet in one sentence and underline its operative words; then build the plan only from that reformulation. Practise by taking 20 past-style sujets and, for each, writing only the reformulation and a two-part problematique in 15 minutes. Keep an examples file organised by theme with, for each example, one sentence stating what it proves - never a bare name or date.
In Culture générale, candidates pile up allusions and quotations (often approximate or misattributed) as decoration rather than using them as arguments, and cite authors they cannot situate.
Candidates believe the jury rewards sheer breadth of references, and they have absorbed lists of citations without checking sources. Under time pressure, approximate attributions slip in (e.g. attributing a phrase to the wrong philosopher), which the correcteur spots immediately.
What to do instead
Limit yourself to a small set of references you can date, contextualise and explain in two sentences each. For every quotation you plan to use, verify the source once during revision and write it on a card with author, work, date and the precise idea it supports. In the essay, introduce each reference with an explicit link ('Comme le montre X dans Y, ... ce qui éclaire le problème parce que ...').
In Français, candidates write a commentaire composé that is a running paraphrase of the text (line-by-line summary) or a dissertation about the theme, instead of analysing how the text produces meaning (lexical fields, syntax, rhythm, figures, enunciation).
Candidates confuse 'explaining the text' with 'telling what the text says'; they lack a method for moving from observation to interpretation, and paraphrasing is the path of least resistance when time is short.
What to do instead
Train the two-step reflex: for every quoted feature, state the procédé, then the effet de sens ('l'anaphore de « ... » insiste sur ... et crée un rythme qui ...'). Build a personal repertoire of procédés by level (lexical, syntactic, rhythmic, rhetorical). Write three full commentaires under timed conditions and have them corrected, checking that no paragraph is a mere summary.
In Français, candidates neglect the technical apparatus of the dissertation or contraction de texte: no clear problématique, a plan that does not answer the sujet, and, for the contraction, they paraphrase or exceed the word limit instead of preserving the argumentative structure with the required proportion of words.
The contraction de texte and the dissertation each impose formal constraints (word counts with a 10% tolerance, preservation of the thèse, no personal commentary) that candidates underestimate; they write by inspiration and discover the constraints at the end.
What to do instead
For the contraction, practise the mechanical routine: number the paragraphs, identify the thèse and the articulation of each step, then rewrite each step in your own words at roughly one quarter of the length, and count words by blocks of 10. For the dissertation, impose a written problématique before any drafting and check every paragraph's topic sentence against it. Do at least four timed contractions with strict word counts.
In Anglais, candidates produce a translation or comprehension answer that is grammatically shaky (tense agreement, articles, prepositions) and calqued on French syntax, and in the written expression they answer the comprehension questions with copied sentences rather than reformulated answers.
Candidates revise vocabulary lists but rarely practise producing correct English under time pressure; they translate word-for-word from French and do not re-read for agreement or word order. Copying from the text feels safe but shows no comprehension.
What to do instead
Keep an error log of your own recurring mistakes (e.g. missing -s, wrong tense after 'since', 'informations' vs 'information') and review it weekly. For comprehension, always answer in a full sentence with your own wording and justify with a short quotation. For translation, identify the verb tense and subject of each French clause before writing the English. Do one timed thème/version per week and correct it against a model.
In Mathématiques, candidates jump into calculations without establishing the hypotheses of the theorems they use (e.g. applying a theorem on continuity or differentiability without checking its conditions) and lose the thread of a multi-part problem by not using the results of earlier questions.
The problems are long and structured so that question 2 often depends on question 1; candidates who skipped or guessed an earlier result cannot proceed and improvise. Under stress they also invoke named theorems loosely to save time.
What to do instead
Before each use of a theorem, write one line stating that its hypotheses are satisfied ('f est continue sur [a,b] et dérivable sur ]a,b[, donc ...'). When you cannot prove an early result, state it as an admitted lemma ('admis') and use it explicitly later. In revision, redo full annales problems end-to-end under time, marking each question that reuses a previous result.
In Sciences physiques, candidates write numerical results without units, without significant figures consistent with the data, and without a stated direction for vector quantities; they also skip the schematic or the bilan des forces before writing equations.
Candidates focus on 'finding the formula' and treat units and diagrams as decoration; calculators give long decimals that get copied blindly. In mechanics and electricity, the absence of a clear force or circuit diagram leads to sign errors and wrong equations.
What to do instead
Adopt a fixed writing routine for every exercise: draw the schematic (forces, circuit, or axes) first, list the data with units, write the literal expression, substitute, then give the result with unit and correct significant figures. For vectors, always give direction and sense. In revision, lose marks deliberately: grade your own past papers against a checklist of unit/significant-figure/vector criteria.
In Sciences de la vie et de la Terre, candidates answer with vague prose descriptions of phenomena (e.g. 'the cell divides', 'the hormone acts') instead of using precise scientific vocabulary and the required reasoning chain of cause and effect, and they ignore the documents provided in the exercise.
Candidates memorise conclusions rather than mechanisms, so they cannot articulate the sequence (stimulus → receptor → message → effector → response). They also treat document-based questions as general-knowledge questions and fail to extract the information the documents contain.
What to do instead
For each major mechanism (nerve impulse, hormonal regulation, photosynthesis, plate tectonics), write a one-page flow diagram with the exact terms and the causal arrows, and rehearse explaining it aloud in 90 seconds. In document questions, always answer in the order: 'je prélève l'information du document' → 'je la mets en relation avec mes connaissances' → 'je conclus'.
In Histoire et géographie, candidates narrate events chronologically without answering the question (récit instead of démonstration), muddle dates and actors, and in geography produce a description of a map or document without structuring it around the terms of the sujet or producing a legible, titled croquis.
The syllabus is vast, so candidates rely on general narrative knowledge and approximate dates; in geography they under-prepare the cartographic exercise and treat the croquis as an afterthought, even though it is graded on specific criteria (title, key, orientation, legibility).
What to do instead
Build a dated timeline and a map-based fiche for each major theme, with five key dates and five key actors per theme, verified against a reliable manual. For essays, impose a plan that explicitly answers the sujet's terms in the introduction. For the croquis, practise a fixed routine: title, key with 4–6 items, orientation and scale, then plot the figures in order of importance; do at least six timed croquis.
In Philosophie, candidates produce a doctrinal exposition of an author's theory (e.g. a summary of Kant's ethics) in response to a problem-based sujet, or they answer a text commentary by paraphrasing the text, without constructing a problem or a dialectical progression.
Candidates learn authors as blocks of content and reproduce them, because constructing a problem requires a genuine intellectual step they have not practised. The pressure of the épreuve encourages reciting what is known rather than thinking about what is asked.
What to do instead
For every sujet, first write the paradox or tension the question contains ('si ..., alors ..., or ..., donc le problème est ...'), then build a plan in which each part answers the previous objection. For the texte commentary, extract the thèse, the argumentative steps and the implicit presuppositions before evaluating them. Practise by writing only introductions and plans (10 sujets in 15 minutes each) and having the problematique criticised.
In the section-specific subject paper, candidates treat the specialised épreuve as a repeat of the general papers and revise only broadly, failing to master the specific exercise formats and depth expected (e.g. for a scientific section, multi-step problems and experimental reasoning; for a literary section, stylistics and textual analysis), and they mismanage time by allocating equal effort to all parts.
The coefficient and format of the épreuve de spécialité differ from the general papers, but candidates prepare with generic revision; they discover the specific demands (depth, rigour, particular exercise types) only in the exam room and run out of time on the highest-weighted part.
What to do instead
Obtain the official format and coefficient of your section's épreuve and build a revision plan around its exact exercise types. Do full past papers under timed conditions, allocating time proportional to marks, and rehearse a fixed order: read all the paper, start with the part you master best, reserve the last 10 minutes for checking. Have at least three papers corrected by a teacher familiar with the section.
In the Épreuves orales, candidates recite a memorised presentation, ignore the jury's follow-up questions or answer them defensively, and are unable to comment on a document or text placed before them because they have never practised speaking under observation.
Oral preparation is neglected in favour of written papers, and candidates rehearse monologues rather than dialogue; stress makes them cling to the prepared script and lose composure when interrupted. Many also lack practice in structuring a spontaneous 10-minute exposé.
What to do instead
Rehearse aloud with a timer and a listener at least twice a week, including a 10-minute exposé with a one-minute plan, and train specifically for interruptions by having the listener ask two follow-up questions each time. For document commentary, practise the routine: read silently, identify the nature and source, extract the main idea, then structure the commentary. Record yourself and review for pace, clarity and filler words.