Negative Addition Neither…nor

Neither…nor  (but not either…or)

NEITHER…NOR	EITHER …OR  (PREFERENCE!)
Use neither…nor for negative addition: Not X  AND not Y. When neither… nor begins a sentence and joins two verbs, the auxillary verb precedes the subject.	The expression either…or is not related to neither nor.  In contrast, it indicates "no preference", one or the other, or a condition
NOUNS Neither the movie nor the play was good.   (singlar verb form)	NOUNS Either the movie or the play was good. I can't remember.
I liked neither the movie nor the play.	I didn't like either the movie or the play. They were both bad.
MODIFIERS The plot was neither believable nor engaging.	MODIFIERS The plot was either believable or unbelievable depending on the viewer's perspective.
The director spoke neither specifically nor excessively about the project.	The director spoke either briefly or excessively about his project  depending on how much free time he had. (one or the other)
INFINITIVES & GERUNDS The actors tried neither to overplay nor to underplay their roles.	INFINITIVES & GERUNDS The actors tried either to overplay or to underplay their roles.  (I don't know what they did, but it wasn't effective in the movie.) (one or the other)
They objected to the movie neither following the book nor keeping the central theme.	They objected to either following the book or keeping the central theme. (one or the other)
VERBS I neither liked nor would recommend the movie.	VERBS Either I like a movie or I hate it. There is nothing in-between. (one or the other)
Neither did I like nor would recommend the movie. Move the auxiliary verb in front of the subject.

Neither…nor Verb Agreement

FORMAL	INFORMAL
Neither..nor is used to indicate  "not one or the other.  The verb agreement is singular. The same word form is used for each item being compared (noun, gerund, infinitive, or phrase.)	Informal use of neither..nor is becoming more common and includes using plural nouns  "not one or others" or "not some or others".  A plural verb is used. In a way, it is like the comparison of "apples and an orange" or visa versa.
Neither I nor my son carries a mobile phone.   (a singluar noun.)	Neither I nor my sons carry mobile phones. (singular + plural noun)
Neither baggage nor equipment was removed from the building.   (a mass noun + a mass noun)	Neither my sons nor I carry mobile phones.  (plural + singular noun)
Neither I nor my son carries a mobile phone.  (singular subject – singular object)	Neither the girls nor the boys carry mobile phones.  (plural + plural noun)
Neither smoking nor drinking is permitted in his house.   (a gerund)	Neither smokers nor drinkers are permitted in his house.
Neither before work nor after work is a good time to meet.  (an adverb phrase)	Neither before work nor after work are good times to meet.

No Preference / Condition

EITHER . . . OR   (paired-conjunction)	EITHER . . . OR ELSE   (conditional clause)
Either you ate the pie or I ate it. I can't remember who did.   (one or the other)	Either you eat the pie, or (else) I will.  (informal Eng. with "either") You eat the pie, or else I will.   (condition, semi-threat)
Either you can eat the pie or I'll eat it. I don't really care who eats it.  (no preference)	You eat the pie. Otherwise, I will.  (condition, alternative)

Common Mistakes

INCORRECT	FIXES
*Not only the Grand Canyon is deep but also is wide.	Not only is the Grand Canyon deep but also wide. (adjective + adjective) Not only is the Grand Canyon deep [is], but also it is wide. (clause + clause) Move the auxiliary verb in front of the subject. When Not only...but also begins a sentence and joins two verbs, the auxillary verb precedes the subject.
*Not only the jokes but also the dialog were good.	Not only the jokes but also the dialog was good. (The verb agrees with closest noun.)
*Neither I took vacation nor I asked for sick leave.	Neither did   I   take vacation, nor did I ask for sick leave. Move the auxiliary verb in front of the subject. When Neither...nor begins a sentence and joins two verbs, the auxillary verb precedes the subject.
*Neither I nor my sons carries a mobile phone.   (Must compare two singlular item.s)	Neither I nor my son carries a mobile phone.

*Yellow highlighted words are examples of incorrect usage.
Pop-Q "NOT only"