Noun vs Verb

Change the following word to a verb:

invitation

(a)  

Change the following word to a verb:

apology

(a)  

Change the following word to a verb:

excuse

(a)  

Change the following word to a verb:

criticism

(a)  

Change the following word to a verb:

sympathy

(a)  

Change the following word to a noun:

compliment

(a)  

Change the following word to a noun:

complain

(a)  

Change the following word to a noun:

accept

(a)  

Change the following word to a noun:

harmonize

(a)  

Change the following word to a noun:

enter

(a)