So, Too, Either, Neither

So and Too
The word 'so' and 'too' are useed to combine two positive statement with identical predicates to form a compound sentences.
Formula:
so + auxiliary verb + subject
subject + auxiliaey verb + too
Example:
Nadya likes playing chess. Shandy also likes playing chess.
-Nadya likes playing  chess and so does shandy
-Nadya likes playing  chess and shandy does too

either and neither

The word 'either' and 'neither' to combine two negative statements with identicalpredicates to form a compound sentence.
Formula:
Subject +  auxiliaey verb + not + either
neither + auxiliaey verb + subject
Example:
alvian is not doing his homework now. VIta is also not doing her homework.
-Alvian is not doing his homework now and vita is not either
-Alvian is not doing his homework now and neither is vita