dummy "it" and the the verb "make"

Question

I really want to know about the relation between dummy "it" and the the verb "make".

These example sentences are from TOEFL, and I collected all of them which includes dummy "it" after the verb "make".

1. A well-kept room making it possible for people to concentrate effectively on their work.
2. Orderly environment makes it easier to process the information, which ensures that tasks are completed more efficiently.
3. The rise in demand for domestic goods causes local companies to increase production, which makes it necessary to hire more workers.
4. It is the lack or gravity on the moon that makes it possible to leap 30feet or more.
5. More and more people are making changes to their lifestyle that are beneficial to the environment.

When I googled about the dummy it after the verb make, it said that it has to be the subject of an infinitive phrase.

However, according to the Cambridge Dictionary, https://dictionary.cambridge.org/grammar/british-grammar/infinitives-and-imperatives/infinitives-with-and-without-to,

it is written that we can use the to infinitive in a clause with a verb that has no subject.

Moreover, example number 5, the sentence is grammatical even if verb make is used without dummy it.

now I am in panic...

Several days I have looked up dictionary and google, but I do not get the right answer..

please help me to understand the syntactic structure regarding make and dummy it with infinitive clause.

Answer 1

In 1-4, it stands for an infinitive verb phrase that appears later in the sentence.

They are:

1. "to concentrate effectively on their work"
2. "to process the information"
3. "to hire more workers"
4. "to leap 30 feet or more"

To avoid the dummy it; one could replace it with the gerund version of each of these phrases, like so:

1. A well-kept room makes concentrating effectively on their work possible for people.
2. An orderly environment makes processing the information easier, which ensures that tasks are completed more efficiently.
3. The rise in demand for domestic goods causes local companies to increase production, which makes hiring more workers necessary.
4. It is the lack or gravity on the moon that makes leaping 30 feet or more possible.

However, using the dummy it and moving the verb phrase later makes these sentences more easily readable. In particular, number 1 moves the verb "concentrating" much closer to "people", who are the ones concentrating, making it much easier to parse.

Your 5th example is not the same use of the word make. The verb make is used with changes or a change to indicate who is causing the change. For example, the same use of make appears in this sentence: I made changes.