What new and different topic could I use to write a thesis in the field of English Linguistics?
A new and different topic would be that of how the prescribed standards of English Varieties (Indian English Variety, Arabian English Variety, etc) are combining or may combine to create new forms in Standard American and Standard British English in the areas of punctuation, vocabulary and syntax. There have developed and have remained differences between American English and British English, differences like these: the British "take chance" and "agree a topic" while Americans "take a chance" and "agree to/on/about a topic."
The interesting thing about communication that has changed is that, because of the flowering of the Internet, speakers of English from all over the world can write and share ideas on the same platform positioning language styles with differing prescribed standards of language next to each other. Observation shows that there is a "bleeding," a spreading, of some standards of one variety over into the standards of other varieties (and into Standard English). The question this observation calls forth is whether this combining of differing prescribed standards will impact traditional Standard American and Standard British English.
Some examples of this bleeding of standards from one variety to another and to Standard American and British English concern vocabulary and punctuation. For instance, Americans speak of doing something "while" they wait, etc, and the British speak of doing something "whilst" they wait. Americans who associate with British speakers or who read British writers on the Internet, because of linguistic accommodation of salient (dominant) phonetic variants, find their language breaking out in whilsts and even amongsts.
As another example, some English Varieties of post-colonial nations use non-Standard punctuation such as a space before line-end punctuation (e.g., "Stop !" "Will you stop ?") since, for that variety, it is the prescribed punctuation; or such as the absence of a space between a word and the parenthetical that is adjacent to it (e.g, "non-government organization(NGO)" "(1)George and Lennie"). Standard English speakers who read the writings of English Variety speakers and who might not ordinarily do so find that they've grown fond of that crowding effect and, perhaps reflexively, omit those spaces between word and parenthetical. Then there are the tortuous Standard English articles: a an the. For a Standard English speaker who reads the writing of English Variety speakers--who omit articles as prescribed by rule in their variety--long enough, the omission of those critical articles can start to make sense!
This new development of accommodation of salient variants certainly presents new and different opportunities for study in English Linguistics: Will the Standard English of American and British English speakers become a blend, an amalgam, incorporating a collection of prescribed variants of many English Varieties or will this tendency to amalgamate remain an Internet phenomenon, silently battled against?
The most recent and active field today in linguistics is how the new electronic media will elicit new paradigms for the study of digital linguistics. In other words, how will such abbreviated techniques as Twitter and Facebook change the way language is used, pronunciation, phrasing, etc. of the English language? Your question did not designate the level of your thesis – master’s, doctorate? – but if you are ready, such topics as digital literary analysis (and digital literature itself), visual rhetoric, pronunciation of digital voice communication, frequent word combination analysis, etc. are all ripe for the next generation of linguistic scholars. You might look at the linguistic implications of emojis, for example, or the effectiveness of translation software. The term linguistics is defined as “the study of language,” but is often applied to the study of the sounds of a language, not merely the syntax (word order) or lexicon (the words in a language).