“Can” vs “Able to”: People/Animals vs. Inanimate Objects
I’m wondering if the English grammar “rule” given below, which I have heard from numerous non-native speakers, has any validity.
“can” is used for people, animals, and inanimate objects.
“able to” is not used for inanimate objects, only for people and animals (animate objects).
Is this an accurate description of current usage? Was it maybe a prescriptive rule from long ago?
Just a quick Google search for “is able to” and “science” shows the following, and all from prestigious publications or institutions:
In this situation the neuron is able to form new connections.
The material is able to store the gas at a much higher concentration
The human brain is able to recognise a familiar object
The enzyme is able to go on chewing up
The new compound, Pentobra, is able to easily punch holes
Solution 1:
As an American English speaker for almost 6 decades, I have never heard this rule, nor does it make much intuitive sense. The examples given all seem entirely appropriate current usage.
Solution 2:
The NMT Crane Hire information website uses "able" when referring to tower cranes which are inanimate machines. In fact the third paragraph of the webpage uses "can" and "able" pretty well interchangeably.
Before we start detailing specific load charts, let’s add in some context for comparison. In the construction of buildings, the typical tower crane can lift an unsupported weight of around 20 tonnes, depending on the conditions, while still being able to move the object around with relative ease.
Of course NMT isn't a definitive language authority, it's a crane hire company, but it was the first one I came to when searching for crane capacity and the page is written in good, if informal, English.
The word 'able' is used to refer to inanimate objects (particularly machines and materials) very frequently in colloquial speech, often as a synonym for 'can'. I would need to be told by a very authoritative source that such a rule existed before I stopped doing so.