Neither I nor she will able to climb the tree.

Neither I or she will able to climb the tree.

Which sentence is right and why?

It is the first one because nor is a proper way of saying another person cant do it.

This is an example of using correct correlative conjunctions:

http://grammar.ccc.commnet.edu/grammar/conjunctions.htm#correlative_conjunctions

The correct sentence is "Neither I nor she will be able to climb the tree."

In this sentence, the correct word "nor" is used to connect the two subjects "I" and "she," which means "neither me" and "nor her." The verb "will be able to climb" is used to indicate the future ability or capability to climb the tree. The word "be" is necessary to form the correct future tense, and "will" is used as the auxiliary verb.

On the other hand, the incorrect sentence "Neither I or she will able to climb the tree" contains multiple errors. Firstly, the word "or" is used instead of "nor" to connect the subjects. Secondly, the verb phrase "will able to climb" lacks the auxiliary verb "be" and does not form a correct future tense. The corrected version of this sentence would be "Neither I nor she will be able to climb the tree."