Verb suffixes:

-en:                      widen, strengthen, lengthen

-ate:                     communicate, irritate, complicate

-ify:                      intensify, magnify, beautify

-is(z)e:                  realise, economise, recognise

Adverb suffixes:

-ly:                       easily, slowly, quickly

-ward(s):              downwards, forwards, afterwards

-wise:                   clockwise, anti-clockwise