I would like to ask if the sentence below is grammatically correct. If yes, could anyone that is familiar with this rule of usage explain how to use it and cover the complete usage?
It's a matter of urgency that the plan be implemented.
As can be seen from this sentence, the word "should" is omitted. As far as I learned about the usage of should, it's omitted when it's used with some verbs such as advise, suggest, command etc.
Thanks in advance.
Your sentence is very correct. It is in the subjunctive mood. From Wikipedia:
The subjunctive in English is used to form sentences that do not describe known objective facts. These include statements about one's state of mind, such as opinion, belief, purpose, intention, or desire.
Your sentence states that it is considered urgent that the plan has to be implemented, but it is uncertain that it will be.
In such cases you don't say "is implemented" but use the infinitive form of "be" and say, "that the plan be implemented". So the only difference is the uncertainty which is the subjunctive.
