Answer:
Pay.
In more general, commonly used, contexts, the plural form will also be pay. However, in more specific contexts, the plural form can also be ( pays ) e.g. in reference to various types of pays or a collection of pays.
Speak.
In more general, commonly used, contexts, the plural form will also be speak. However, in more specific contexts, the plural form can also be ( speaks ) e.g. in reference to various types of speaks or a collection of speaks.
Go.
The plural form of go is ( goes ).
