Anglais · Bac Sciences Mathématiques

Expressing Cause and Effect

Explaining why something happens, and what happens as a result, is one of the most useful writing skills — and the single most tested error point is the difference between "because" and "because of".

Learning objectives

  • Distinguish between 'because' (+ clause) and 'because of' (+ noun phrase)
  • Use since, as, due to and owing to correctly to introduce a cause
  • Use thanks to to introduce a positive cause
  • Use expressions of result such as as a result, therefore, consequently and so
  • Use verb patterns such as lead to, result in and cause to link a cause and its effect
  • Combine two related sentences into one sentence expressing cause and effect
  • Identify the cause and the effect within a given sentence

Grammar & vocabulary

Because vs. because of — the key distinction

because + subject + verb (a full clause): "She was tired because she had worked all day." because of + noun / gerund (a noun phrase, no separate subject and verb): "She was tired because of the long working day." "He was late because of missing the bus." The grammar rule is simple: if what follows has its own subject and verb, use "because"; if what follows is just a noun, pronoun or -ing form, use "because of".

Other ways to introduce a cause

since and as (+ clause, often at the start of a sentence, usually for a reason already known to the listener): "Since it was raining, we cancelled the picnic." "As she had no money left, she couldn't buy the book." due to and owing to (+ noun phrase, more formal than because of, often used in writing): "The flight was delayed due to bad weather." "Owing to a technical problem, the show was postponed." thanks to (+ noun phrase, used for a positive cause): "Thanks to her hard work, she got the scholarship."

Expressing the effect or result

as a result (of), as a consequence, therefore, consequently, so — all introduce the result of a cause already mentioned: "There was a heavy storm. As a result, several flights were cancelled." "He didn't study for the exam; therefore, he failed it." "It was very hot, so we stayed indoors." Note the punctuation: "as a result", "therefore" and "consequently" are usually followed by a comma when they begin a sentence, while "so" simply connects two clauses without one.

Verb patterns linking cause and effect

X leads to Y: "Lack of sleep leads to poor concentration." X results in Y: "The new policy resulted in higher sales." X causes Y: "Smoking causes serious health problems." the cause of X is Y: "The cause of the accident was a mechanical failure." These patterns are especially useful for explaining scientific or social phenomena in a formal, objective tone.

Effect vs. affect

effect is normally a noun meaning a result: "Pollution has a serious effect on health." affect is a verb meaning to influence or have an impact on: "Pollution affects our health." Keeping this distinction clear avoids one of the most common vocabulary mistakes in cause-and-effect writing.

Common mistakes

1

Following 'because of' with a full clause instead of a noun phrase — 'He was late because of he missed the bus' is incorrect; the correct form is 'He was late because he missed the bus' or 'He was late because of missing the bus.'

2

Following 'because' with a noun phrase instead of a clause — 'She stayed home because the rain' is incorrect; the correct form is 'She stayed home because of the rain' or 'She stayed home because it was raining.'

3

Confusing 'effect' (a noun, meaning a result) with 'affect' (a verb, meaning to influence) — 'The heat will effect the harvest' is incorrect; the correct form is 'The heat will affect the harvest', while 'The effect of the heat was visible' is correct.

4

Using 'due to' at the very start of a sentence in strict formal style without a linking noun phrase — some style guides prefer 'owing to' or 'because of' at the beginning of a sentence, though 'due to' is now widely accepted in everyday English.

5

Writing 'result to' instead of 'result in' — 'The strike result to delays' is incorrect; the correct form is 'The strike resulted in delays.'

Worked example — Why the trip was cancelled

Passage

"Our school trip was cancelled because of the heavy snow that fell overnight. Since the roads were too dangerous to drive on, the school decided to postpone the trip to the following week. As a result, many students were disappointed, but they understood that safety came first. Thanks to the quick decision of the teachers, no one was put at risk."

Explanation

"because of the heavy snow" uses because of + noun phrase, correctly, since no clause with a subject and verb follows. "Since the roads were too dangerous" uses since + a full clause (subject "the roads", verb "were") to introduce a known reason. "As a result" introduces the consequence (disappointed students) of the cause already given. "Thanks to the quick decision of the teachers" uses thanks to + noun phrase to introduce a positive cause, matching the positive result (no one was put at risk).

3 practice exercises

Exercise 1

Easy

Choose because or because of. 1) The match was cancelled ___ the storm. 2) She passed the exam ___ she studied hard. 3) He couldn't sleep ___ the noise. 4) They stayed inside ___ it was too cold.

Show answer

1) because of 2) because 3) because of 4) because.

Exercise 2

Medium

Combine each pair of sentences using the linking word in brackets. 1) It rained heavily. The match was postponed. (as a result) 2) He didn't revise. He failed the test. (due to) 3) She practises every day. She has become an excellent player. (thanks to)

Show answer

1) It rained heavily. As a result, the match was postponed. 2) He failed the test due to his lack of revision. 3) Thanks to her daily practice, she has become an excellent player.

Exercise 3

Hard

Identify the cause and the effect in each sentence, then rewrite it using a different cause-and-effect expression. 1) "Since the roads were icy, many drivers had accidents." 2) "Pollution levels have risen, so more people are developing respiratory problems."

Show answer

1) Cause: the roads were icy. Effect: many drivers had accidents. Rewritten: "Many drivers had accidents because of the icy roads." (or: "The icy roads led to many accidents.") 2) Cause: pollution levels have risen. Effect: more people are developing respiratory problems. Rewritten: "Rising pollution levels have resulted in more people developing respiratory problems."

3 exercices, c'est un début.

Orka en génère autant que tu veux sur ce chapitre, à ton niveau, avec correction détaillée étape par étape.

Continue gratuitement sur Orka

Va plus loin sur ce chapitre

FAQ

What is the difference between 'because' and 'because of'?

'Because' is followed by a full clause with a subject and a verb — for example, 'because it rained'. 'Because of' is followed by a noun or a gerund, not a clause — for example, 'because of the rain'. Using a full clause after 'because of' ('because of it rained') is a common and incorrect mistake.

What are some common expressions for showing effect or result?

Common expressions include 'as a result', 'therefore', 'consequently', 'so', and phrases like 'X leads to Y' or 'X results in Y', all of which introduce the consequence of a cause that was already mentioned.

Can 'due to' and 'owing to' be used in the same way as 'because of'?

Yes — 'due to' and 'owing to' are both followed by a noun phrase, just like 'because of', and can generally be used interchangeably with it, though 'due to' and 'owing to' are more common in formal or written English.