In the sentences
This is the only study on/into the effect of X in aquatic birds.
The studies on/into aquatic birds have been carried out on species A and B.
Which word do we use?
Learner’s Dictionary defines ‘on’ as:
used to indicate the subject of something
• a book on [=about] North American birds
• a discussion on current events
and ‘into’ as:
relating to or concerning (something)
• an investigation into the causes of the accident
Am I right in thinking that ‘into’ is used in these contexts when the study is about the result of an action (based on Google searching for both usages)?
i.e. ‘study on birds’ and ‘study into the effect of X’. Or can they be used interchangeably?
Best Answer
You can't reliably predict which preposition will be used in any particular context from its dictionary definition—see my Answer here. You have to learn, word by word, which particular preposition each verb, adjective or noun ‘selects’ or ‘licenses’ to express a particular meaning or relationship.
For instance, the verb study casts its field or topic as a direct object—we studied the effect of X on aquatic birds. When transitive verbs are nominalized, their direct objects are most often cast as preposition phrases headed by of:
Nominal study also licenses on PPs:
But of would be preferred if you went on to use an on PP as complement of a different word, with a different sense:
Study does not license into PPs as complements, either as a noun or as a verb. You would find an into PP following study only as an adjunct or complement of another consituent:
The verb investigate likewise casts its field or topic as a direct object—we investigated the effect of X on aquatic birds—and its nominal derivative investigation likewise licenses of PPs:
Investigation, however, also licenses into PPs:
Here investigation is metaphorically treated like a process of digging into a formless mass to find the relevant information, as if with a probe or shovel.
The into construction tends to be used mostly in contexts where investigation designates the process of investigating—we are conducting an investigation into the effect of X. It is unusual to find into used when investigation designates the outcome—in the title of a paper, for instance, where the results are reported.
Often the nominal derivative will license the same prepositions as its mother verb. But this doesn't usually run backwards, from the noun to the verb. For instance, we never say:
These are not hard and fast “rules”, but they reflect ‘standard’ formal usage.