Discussion Groups / English Usage / January 2009

That would be more grammatically correct.

That is right. If you omit your wife, the sentence becomes:

 “I have not decided to go.”

If you omit yourself it becomes:

 “My wife has not decided to go.”

If you write it in full with the positions of you and your wife interchanged
it becomes:

 “Neither I nor my wife has decided to go.”

Where you need to choose between "have" (for first and second person singular)
and "has" (for third person singular) you use the one that fits the nearest of
the singular pronouns or nouns.

The rule for the number of the verb when the subject is compound with
its parts joined by "or" or "nor" is:  the verb agrees in number with
the part of the subject closest to the verb.  "He (n)or they are/go/
want..."  "They (n)or he is/goes/wants..."  If both parts are singular
("he or she"), so is the verb, because there is no plural part for the
verb to agree with.

Unfortunately, hardly anyone knows this.  I hear "he or she are" all
the time, often in scripted news broadcasts and in scripted TV shows.
I read it all the time, in novels published by large NY publishers.
Going back a decade or more!