Usage notes

* Whether it is proper to use "firstly", rather than "first", has often been disputed. ** Beginning in the early 19th century with de Quincey, who erroneously believed that "firstly" was a neologism, some have argued against the use of "firstly", advocating the sequence: "First", "secondly", "thirdly", .... ** The usage of "firstly" is also deprecated by some modern style guides. International English Usage The Chicago Manual of Style further recommends that all such -ly forms be avoided, and that list items begin only with "first", "second", and so forth. ** Other authorities disagree. *** The American Heritage Dictionary comments: ***: It is well established that either first'' or ''firstly'' can be used to begin an enumeration: ''Our objectives are, first'' (or ''firstly''), ''to recover from last year's slump. *** The Oxford English Dictionary'' notes the dispute but does not pass judgment: "many writers prefer ''first'', even though closely followed by ''secondly'', ''thirdly'', etc." "Firstly" in the ''Oxford English Dictionary , online edition (subscription required) ** "Firstly" may appear more formal than "first" and is often recommended for the formal enumeration of arguments. Writing in a Formal Style for Academic Purposes