"It has been suggested that the company invest in new machinery".
"It is essential that every child have educational opportunities".
If I want to write something like the above sentences, how could I know that now I have to write my verbs in the subjunctive mood ? Why we use the subjunctive mood in AmE?
If someone also shows how to make thses sentences rewritten using "Should" as it is used in BrE that will be great.