For practical purposes, this study focuses exclusively on those formulaic expressions that consist of two words or more, represented at the top of Figure 1, overlapping with multiword expressions. Such overlap indicates that not all multiword expressions may be formulaic. Furthermore, the area of one-word expressions that overlaps with formulaic language indicates that there are one-word formulaic expressions, such as please, sorry, thanks, etc. Formulaic language may also overlap with some phrasal verbs (e.g. carry out [a task]) but some phrasal verbs may not be considered formulaic (e.g. take out).
Moreover, dealing with a technical corpus, I found that some expressions that could be considered terms, though not highly specialized, could also be considered formulaic in nature (e.g. terms and conditions, code of practice), hence the overlap between terms and formulaic expressions. The overlap is not complete, as not all termsmay be formulaic. All this goes to show that the boundaries of formulaicity are very blurry and that it will not be possible to establish very clear dividing lines between formulaic expressions and non-formulaic expressions or between the various classes of formulaic language.