Oxford's letter of 24 November 1569 is one of many that survive, falling roughly into five groups: personal letters 1563 to 1604, mostly to William and (later) Robert Cecil (44); draft interrogatories, January 1581 (2); personal memoranda, 1591 to 1597 (4); letters on Cornish tin-mining 1595 to 1599 (18); memoranda on the same 1595 to 1599 (9). Seventy-four items are entirely in Oxford's italic hand, while two are partly and one entirely in the hand of an amanuensis. The total number of words surviving from Oxford's pen surpasses 50,000. Oxford's hand is almost always a clear and legible italic. Before 1569 and after the Queen's death in 1603 his signature is also italic; between these dates it contains distinctly antique letter-forms.

With respect to general habits of spelling, Oxford falls about midway between the untrained and phonetic practices of the poet Thomas Churchyard or the landlady Julian Penn (1592), and the more nearly uniform and ‘modern’ practices of William Cecil, Oxford's daughters Bridget and Susan, and his second wife, Elizabeth Trentham.

The opening sentence of Oxford's first known letter in English (see p. 51) may be taken as representative:

The vocabulary is recognizably English, virtually every word resolvable into a modern equivalent. Since internal punctuation is sparse (a single comma), it is necessary to parse the sentence, inferring a break or pause, for example, between ‘syknes’ and ‘yet’. Some compounds must be read differently from their modern equivalents. Thus, for example, ‘lokinge to’ represents the compound ‘looking-to’, meaning ‘oversight’ or ‘observation’. The clause ‘yt hathe visited me of lat wythe syknes’ contains an impersonal pronoun as subject, as in ‘it is raining’.

Oxford's consonants are familiar, except perhaps for ‘v’ and ‘u’: historically these are one letter of the Latin alphabet, normally ‘v’ in initial positions, ‘u’ in medial positions, so that ‘visited’ and ‘vnto’, ‘haue’ and ‘ouer’, reflect contemporary practice. Distinctly odd even for the time is the ‘th’ (elsewhere ‘t’ and ‘the’) which terminates ‘althoth’.