I have just encountered the following phrase:
It is important that each player not know what the other player will do.
Why is it written here "not know" and not "not knows"? Also would it be correct to say "...player does not know..."?
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Sign up to join this communityI have just encountered the following phrase:
It is important that each player not know what the other player will do.
Why is it written here "not know" and not "not knows"? Also would it be correct to say "...player does not know..."?
This is the Subjunctive Mood. People will avoid using it by rephrasing their sentences all the time without noticing it, many times with an infinitive. In here, one would usually say it like this
It is important for each player not to know what the other player will do.
This site has good information about the subjunctive. On the site there is a list of verbs and phrases that are followed by the subjunctive (I pasted them here in case the link breaks someday).
Verbs followed by the subjunctive: to advise (that) to ask (that) to command (that) to demand (that) to desire (that) to insist (that) to propose (that) to recommend (that) to request (that) to suggest (that) to urge (that)
Source, Language Dynamics
Phrases followed by the subjunctive: It is best (that) It is crucial (that) It is desirable (that) It is essential (that) It is imperative (that) It is important (that) It is recommended (that) It is urgent (that) It is vital (that) It is a good idea (that) It is a bad idea (that)
Source, Language Dynamics
In the subjunctive, the he, she, it form of the verb takes the same verb form as the others, as you noticed in the sentence you saw.
Just keep in mind, like FumbleFingers said in his/her comment above, the subjunctive is not used very often, but it's pretty cool!
I am not a native speaker but I have never had any issues with that. Let me explain the logic behind this phenomenon: We deal with "invisible" modal verb "should" in this kind of sentences. It is important that each player (should) not know what the other player will do. The same logic applies to similar structures: it is necessary that she (should) do it. It is required that he (should) be here at 5 p.m.