b2o wrote:Could someone please explain me why "ignition" and "flames spreading" are not parallel?
As a non-native speaker I see ---, making noun + adjective and gerund (serving as a noun) + adjective. So, it looks quite parallel to me.
Look at
making ignition much easier and flames spreading more quickly.
For clarity we can rewrite it as
making ignition much easier and making flames spreading more quickly.
For starters this form does not work.
making flames spreading more quickly
What that conveys via making-noun-verb-ing modifier is that flames that spread more quickly are being made, as in making flames. What kind of flames? Flames that are spreading more quickly.
What the sentence is seeking to convey is that the flames are being made to spread more quickly. The way to convey that is the following.
making flames spread more quickly
As far as parallelism goes, to see the issue in the original version look at what we have given the meaning I just outlined.
making ignition easier and flames spreading more quickly
making ignition easier This conveys that the ignition is
being changed so that it is easier.
making flames spreading more quickly This conveys that flames are
being created.
So essentially two different meanings of make are being used in the same list.
The following is a clearly parallel construction.
making ignition easier and the spread of flames more rapid
I believe the following works also, but I am not 100% sure it does, as
ignition easier is noun-adjective, while
flames spread more quickly is noun-verb-adverb.
making ignition easier and flames spread more quickly
It looks good to me though.
How is ignition being changed? It is being made easier.
How are flames being changed? They are being made to spread more quickly.
That seems basically parallel.