Grammar- is using versus is by using

Hello,


What are the differences between the two following sentences? Is one sentence more preferable than the other?

Sentence A.   One way of lowering fuel consumption is using public transport.

Sentence B.   One way of lowering fuel consumption is by using public transport.


Thank you.

With best wishes

I wish to present a different way of looking at the sentences.

One way of lowering fuel consumption is using public transport.
(You can rewrite as: Using public transport is one way of lowering fuel consumption.)

' Using public transport' is a noun phrase having a dual-function role here:

1) being complement of the verb (of incomplete predication) 'is' and

2) in apposition with the noun 'way'.

One way of lowering fuel consumption is by using public transport.

(Here you can't rewrite as: By using public transport is one way of lowering fuel consumption.)

We normally say by doing something, you get/achieve something.

So, the sentence needs to be rephrased as - One can/will lower fuel consumption by using public transport

or By using public transport, one can/will lower fuel consumption.

' By using public transport' here is an adverb phrase of manner modifying the verb 'can lower or will lower'.

Hello,


I have recently found 'by using public transport' in the following sentence is closely connected with the prepositional phrase in LEO. Therefore, it should be a prepositional phrase that followed 'One way of lowering fuel consumption is'.
 
One way of lowering fuel consumption is by using public transport.

The best time to practice water conservation is before a water shortage.   (prepositional phrase = noun functioning as a  complement)
LEO-prepositional phrase= preposition + object of the preposition + modifiers.

As for the noun phrase 'using public transport', it can also function as a gerund phrase according to the example below shown by LEO.

One way of lowering fuel consumption is using public transport.

One of Serena Williams' biggest disappointments after her semifinal defeat was losing her spot for tennis singles in the Olympics.  (gerund phrase = complement)
LEO- gerund phrase = gerund + modifiers, objects, or complements.

I am only a learner of English, I hope the experts or grammarians can correct this reply.


Thank you.

With best wishes.