Trickiest is apparent or apparently - these are used whether something appears to be the case on the surface (superficially) but in fact you are inclined to doubt it - that is you suspect that in truth it is not the case. In a sense such statements are weak assertions, but there is a negative strength due to the dubious overtones (you are expressing doubt).
Intermediate is evident or evidently - these imply that you have some evidence that something is the case and in fact you are inclined to believe it - that is you suspect that in truth the assertion holds. In a sense such statements are stronger assertions, but there is a negativity due to deliberately opening the statement up for contradiction by further evidence.
Stronger still is obvious or obviously - these imply that there is little room for doubt. Nonetheless the fact that something is thought obvious (even by a great many people) does not mean that it is actually true. In science (or linguistics), we often take the obvious and try to formally prove or disprove it. Sometimes we find that the obvious is false, or only a first approximation, and a new theory supplants the old. Or putting it another way, we start to believe theories that are very non-obvious or counter-intuitive (think relativity, quantum mechanics, round earth, earth going round the sun; words and sentences are concepts in linguistics that do not have an obvious definition that survives across languages).
To add another case, supposed or supposedly - imply that something is thought to be the case and leaves room for doubt (with the -s- pronounced /z/), but trickily supposed to can mean that something should be the case, is expected to be the case, or is meant to be the case (with the -s- pronounced /s/). Here we have two different connotations depending on whether we pronounce it with a voiced or unvoiced sibilant (/s/ or /z/).
E.g. it is not obvious why "into" should be regarded as one word and "out of" as two words; or when space,' ', hyphen, '-', semicolon, ';', or comma, ',' or fullstop, '.' should be used to separate words, phrases or clauses (this takes us into the realm of stylistic orthological convention rather than grammar - and represents written conventions leaking back into oral speech).
So "out of" is apparently two words in English but "into" is evidently one word; "come in" is apparently two words in English, but is supposedly one (einkommen) in German even though it is often split up (kommen ... ein).
"I came, I saw, I conquered!" is obviously one sentence, three words in Latin, but
"I came! I saw! I conquered!" is apparently three sentences!
"She was supposed to have killed him!" has two different meanings depending on how you pronounce it.
"There are two ways of constructing a software design...
One way is to make it so simple that there are obviously no deficiencies,
and the other is to make it so complicated that there are no obvious deficiencies."
- C A R Hoare