slowly

Some commentators claim that careful writers avoid the adverb slow, in spite of the fact that it has had over four centuries of usage.

• • have a continent forbearance till the speed of his rage goes slower
  • —William Shakespeare

In actual practice, slow and slowly are not used in quite the same way. Slow is almost always used with verbs that denote movement or action, and it regularly follows the verb it modifies.

• • beans … are best cooked long and slow
  • —Louise Prothro

Slowly is used before the verb

• • a sense of outrage, which slowly changed to shame
  • —Paul Horgan

and with participial adjectives.

• • a slowly dawning awareness … of the problem
  • —Amer. Labor

Slowly is used after verbs where slow might also be used

• • burn slow or slowly

and after verbs where slow would be unidiomatic.

• • the leadership turned slowly toward bombing as a means of striking back
  • —David Halberstam