Causes can be shown by prepositions as well as by conjunctions and connectors. The prepositions vary slightly in meaning and use
THE VARIETY OF CAUSE WORDS IN ENGLISH
Causes can be expressed in numerous different ways. Many are mentioned in the post 32. Expressing Consequences, while the cause-showing uses of conjunctions and connectors are detailed under 40. Conjunctions versus Connectors and 61. “Since” versus “Because”.
Prepositions showing a cause are fairly important too; they include through, with, out of, because of, as a result of, due to, owing to, on account of, thanks to and courtesy of. Most, it is clear, are multi-word, ending in an ordinary preposition. They are sometimes equivalent to each other and sometimes not. This post is mainly about the differences between them.
The preposition status of the above expressions is shown by the fact that they must be accompanied by a noun, pronoun or -ing verb (see 84. Seven Things to Know about Prepositions). Consider this:
(a) Children are vulnerable because of their trust in adults.
None of the words after because of here is a verb. The key word trust is a noun. If we wanted it to be a verb, we would have to say (their) trusting after because of or switch to the conjunction because followed by they trust. More details of this difference between because and because of are in the post 61. “Since” versus “Because”.
ADJECTIVAL VERSUS ADVERBIAL USES
Most combinations of a preposition and its noun can be used like either an adjective (saying something about another, earlier noun) or an adverb (saying something about a verb, adjective or whole sentence). This variability of preposition phrases is extensively illustrated in the posts 53. “As”, “Like” and “Such As”, 56. Comparing with “Like” and “Unlike” and 84. Seven Things to Know about Prepositions.
Here is how because of can act in the two different ways (the described word being in capitals each time):
(b) ABSENCE from work because of sickness costs a great deal. (ADJECTIVE USE 1)
(c) The country’s sports SUCCESS was because of government funding. (ADJECTIVE USE 2)
(d) Malaria SPREADS because of poverty. (ADVERB USE)
Here, the two adjective uses reflect the two main positions of adjectives in English (see 109. Placing an Adjective after its Noun). In (b), the because of phrase is right next to the noun that it describes, absence (from work). In (c), there is also a preceding noun, success, being described, but it is separated from because of by a link verb (was). In (d), because of is adverbial because it explains a verb, spreads. It is also adverbial in (a), where it explains an adjective (vulnerable).
In older grammar books, one of the differences between the causal prepositions listed above involves the adjectival and adverbial uses. Due to is said in these books to be usable only in the adjective ways, while owing to is held to be solely adverbial. Hence, these books would rule out the use of due to in (a) and (d), and the use of owing to in (b) and (c). However, many mother-tongue speakers of English seem unaware of this difference today, so that due to in particular is increasingly heard in both uses.
The causal meaning of with is always adverbial. For it to be present, with must be at the start of its sentence before a noun and following participle, like this:
(e) With its supplies exhausted, the group had to return to base.
For more details of this usage, see 88. Exotic Grammar Structures 1, #7.
As a result of seems usable in both the adjective and the adverb ways. However, its adjective-like use has a variation: it can easily go straight after its noun, but if placed straight after the verb BE in sentences like (c), it usually drops as leaving is/was a result of … .
Out of seems to be more adverbial than adjectival, like owing to, but is perhaps more informal. Even because of may be slightly restricted. Composing example (c) above – illustrating the use after verbs like BE – proved surprisingly difficult. In many potential examples, due to seemed more natural, or there was a temptation to use the conjunction because (+ verb) instead.
OTHER SPECIAL USES
Many years ago, when I used to assess the academic writing of French-speaking students, I noticed that they used thanks to more frequently than I was accustomed to seeing in English, and that in some cases because of seemed better. Knowing a little French myself, I quickly realised that thanks to was a direct translation of grâce à, which, I guessed, was more common in French than thanks to is in English. To help the students, therefore, I needed to work out exactly when thanks to is appropriate in English and when it is not.
I believe thanks to is slightly more emotive than the other causal prepositions: it seems often to indicate not just a cause but also the writer’s feeling about it. It thus resembles, to some extent, the opinion-showing vocabulary discussed in the post 107. The Language of Opinions. This emotiveness must come from the basic meaning of thanks: communicating gratitude to another person for receiving a service or object from them.
Here is a typical thanks to sentence:
(f) Thanks to everyone’s hard work, the road was soon clear.
This sentence does more than explain why the road became clear; it also conveys the speaker’s gratitude to, and even praise of, the workers. Gratitude, however, is not always the message of thanks to. When the result (not the cause!) is clearly unpleasant, criticism can be understood instead:
(g) Thanks to the policies of the Government, the economy is in a mess.
In the underlined result here, it would be hard to interpret the negative word a mess as something desirable or praiseworthy, and hence the cause cannot be receiving gratitude and will be understood instead as an object of criticism. The use of a normally positive word like thanks to express an opposite meaning is an example of that peculiar English habit of irony, similar to saying that a boring experience had been “wonderful” or an unpopular politician was “universally loved”.
Now here is a sentence from an academic context, where thanks to would be less appropriate because a neutral, non-emotive message is required:
(h) Cats fight less in the wild because of the greater size of their territory.
Using thanks to here would probably suggest that large-sized cat territory was a good thing (reduced cat-fighting being also good). Using because of (or owing to or on account of), on the other hand, gives no clue about the desirability or otherwise of large cat territories, but instead keeps attention focussed on the factuality of the sentence.
Courtesy of is similar to thanks to in expressing gratitude about a cause. However, it perhaps also suggests that the cause is a person who has consciously offered their help. An example might be:
(i) This road was built courtesy of a donation from the Mayor.