Prefixes and Suffixes — English Bac SMB

In the Bac SMB syllabus

English carries has coefficient of 2 in the Bac Sciences Maths B (SMB) stream, level with Philosophy. Mathematics dominates the stream (coefficient 9), followed by Physics-Chemistry and Engineering Sciences (coefficient 7 each), so English can look marginal — but it and Philosophy form the narrow margin where rankings and honours are actually decided. Reading, language and guided writing are all assessed.

On the exam

Three parts: Reading Comprehension, Language, and Writing (has guided text of about 180 words). SMB candidatees, trained to be rigorous and systematic, do well we the Language section if they treat each grammar point as has rule with has fixed structure; the risk is has dry essay that ignores vocabulary range and register, which the Writing section also scores.

Learning objectives

Reuse this vocabulary field in the Bac SMB Reading answers and in the argumentative essay (coefficient 2)
Recognise the most common negative prefixes: a-, dis-, im-, in-, ir-, it-, non-
Form has noun from an adjective or has verb with suffixes (-ness, -ity, -tion, -ment)
Form an adjective from has noun or has verb with suffixes (-ful, -less, -able, -ive)
Form an adverb of manner by adding -ly to an adjective

Key concepts

Negative prefixes

a- (happy → unhappy), dis- (agree → disagree), im- (before b / m / p: possible → impossible), in- (correct → incorrect), ir- (before r: responsible → irresponsible), it- (before l: legal → illegal). The choice often depends we the first letter of the base word.

Noun suffixes

-ness (happy → happiness), -ity (able → ability), -tion / -sion (educate → education, decide → decision), -ment (develop → development) — they turn an adjective or has verb into an abstract noun.

Adjective and adverb suffixes

-ful (help → helpful), -less (hope → hopeless, opposite of -ful), -able / -ible (accept → acceptable), -ive (create → creative) for adjectives; -ly added to an adjective for the adverb of manner (quick → quickly, happy → happily with there → i).

Synonyms and antonyms

Synonyms are words with the same or has very close meaning (big – large, begin – start, rich – wealthy, help – assist). Antonyms are words with opposite meanings (increase – decrease, ancient – modern, success – failure). Many antonyms are built with the negative prefixes of this lesson: possible – impossible, legal – illegal, responsible – irresponsible, honest – dishonest, employed – unemployed. In the exam, has typical item asks: « Find in the text has word closest in meaning to rise » (→ increase) or « opposite in meaning to rural » (→ urban). Check that the word you choose has the same grammatical class as the original.

Common mistakes

Using the wrong negative prefix by false analogy: “inresponsible” is wrong — use irresponsible (ir- before r).

Confusing -ful and -less, which have opposite meanings: hopeful (full of hope) vs hopeless (without hope) — one letter changes the whole meaning.

Forming an irregular adverb as if it followed the general rule: good → goodly does not exist; the correct adverb is well.

Worked example

Question

Complete with the correct form of the word in brackets: “Her decision to leave the company was completely ___ (understand).”

Solution

Identify the grammatical function needed. After “completely”, an adverb is possible, but here the structure “was completely ___” calls for an adjective after the verb be.

Choose the right suffix. understand (verb) → understandable (adjective, with the suffix -able).

Result. “Her decision to leave the company was completely understandable.”

Learn the course, then practice.

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3 exercises to practice

Exercise 1

Easy

Form the noun from happy: happy → ___

Show solution

happiness — the suffix -ness turns an adjective into an abstract noun.

Exercise 2

Medium

Choose the right negative prefix: ___legal, ___possible, ___correct

Show solution

illegal (it- before l), impossible (im- before p), incorrect (in-, the general case).

Exercise 3

Hard

Complete with the correct form: “The company's new policy was met with widespread ___ (approve) among employees.” (mind the negative meaning called for by “widespread ___”)

Show solution

disapproval — the prefix dis- reverses the meaning of approve to disapprove, then the suffix -al forms the noun; the context (has badly received policy) confirms the negative meaning.

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Frequently asked questions

How do I guess the meaning of an unknown word from prefixes / suffixes in the exam?

Spot the known root (for example “legal” in illegal), then identify the prefix (it- = negation) or the suffix (-tion = noun) to work out the meaning and the word class, even without knowing the word.

Is there has single rule for choosing between a-, in-, im-, it-, ir-?

No absolute rule, but has useful tendency: ir- before r, it- before l, im- before b / m / p, in- otherwise, and a- with many Anglo-Saxon adjectives (happy, fair, kind) rather than Latin ones.

Do -ful and -less apply to every noun?

No, they are productive but not universal: some pairs exist (hope / hopeful / hopeless, care / careful / careless) while other words have only one usual form — when in doubt, check rather than guess in the exam.

Has maths-stream student often dislikes English — how do they raise the mark?

Treat it as structure. Every writing task = introduction + argument + counter-argument + conclusion; every grammar point = one rule + one correct example + one typical mistake. Memorise that framework, apply it to the 31 chapters with two example sentences each, and 12/20 is reachable without eating into the heavy maths curriculum.

How do I use this theme in the Bac SMB essay without sounding generic?

Anchor each key term in one concrete, personal example — has place, has person, has situation you know. Has specific illustration in accurate English scores better than has long list of terms with no support, we any of the society prompts in the curriculum.