These extremes of likelihood are also present in legal English, besides general English.
Based on 16 years of analysing legal texts, I identified seven stages of likelihood.
(1) absolute certainty
it + is + absolutely + certain + that + subject + verb
e.g.: It is absolutely certain that the omission was not prejudicial to the defendant.
(2) strong likelihood
it + is + highly + possible + that + subject + verb
e.g.: He asserts that it is highly possible that those judges have formed a biased opinion against him.
(3) reasonable likelihood
chances + are + that + subject + verb
e.g.: Chances are that the lawsuit will take place in the country where the tort took place.
(4) slight likelihood
there + is + slight + likelihood + that + subject + verb
e.g.: There is a slight likelihood that the hearing will vary the decision…
(5) reasonable improbability
person + may + not + have + verb3
e.g.: He may not have suffered any monetary loss.
(6) strong improbability
it + is + extremely + unlikely + that + subject + verb
e.g.: It is extremely unlikely that access will be allowed to the property in advance.
(7) absolute impossibility
communication + can + not + be + true
e.g.: These allegations cannot be true.
High detail, easy and fast comprehension. The book entitled 'A Practical Guide to English for Law' describes likelihood in 20 pages, together with 1550 legal terms in 1000 pages and 50 chapters.
The topic of likelihood in legal English is also described in high detail in the PDF ebook entitled 'A User-Friendly Legal English Grammar'. Please take a look at it under menu item "Shop".