Oh, it might be, actually, at least indirectly, because に as a verb form is essentially the equivalent of… であり? It’s the masu-stem of なり. (‘Masu-stem’ isn’t the right technical term, especially since I don’t think にます actually existed at any point, but Japanese uses the same word – 連用形 – for the thing that acts as the masu-stem.) If you know that the て-form is historically just the masu-stem + て followed by sound changes, well… that means that にて is essentially the て-form of the equivalent of だ・である。
I think in the first sentence you’d use 如く rather than 如しに. 如し is an auxiliary verb, not a noun, and is essentially analogous to (の)ようだ, with 如き and 如くbeing conjugations of it analogous to (の)ような and (の)ように/で respectively, hence 如く being the appropriate form to use.
I feel like みたい is more natural, but also a lot more casual. I also recall there being some nuance of the similarity expressed by みたい being visual, or at least bearing some visual/visible characteristics, but I’m not quite sure whether that’s the case, and it doesn’t always seem to fit. Depending on what you’re trying to express though, there might be a better fit (I’m not sure what you mean by sleeping like a bird).
From what I gather 如し/如き/如く isn’t really used anymore, it’s a bit archaic and has almost entirely been replaced by some variation of よう depending on which you use. So instead, 鳥のように寝ました might be more natural/less archaic, and still somewhat formal.
っぽい might actually be so casual it feels out of place in a sentence ending in 〜ました Not sure about that though.
EDIT: Actually, searching for っぽいです does give results, so maybe it can be used in polite sentences just fine.
But doesn’t that also carry a different connotation than みたい or のように? I can’t quite explain it, but it has a different “feel” to me, maybe closer to らしい than to みたい in describing some kind of “inherent” characteristic, so something like 女性っぽい feels to me more like “feminine” than “resembling a girl” whereas 女性みたい is more “resembling a girl” than “feminine” (you know, aside from the considerable overlap between those). Does that track with your interpretation of it?
Ah, it was my understanding that 如し does in fact take the place of a predicate or verb, but I’ll admit I basically learned about it on the spot so there’s a good chance I misunderstood something here or there
Yes, definitely. I wouldn’t say they mean the same thing, but ultimately it depends on what wants to say. The っぽい was just a low ball from me, sorry
Regarding みたい I’ve seen it more at the end of a sentence clause in a similar way らしい is used in that position and sometimes らしい after nouns (as you said, emphasizing “Y having the features of X” in a XらしいY sentence), but みたい not as often. I’ve seen のような or のように way more often in general.
I think technically a 助動詞 is anything that goes at the end of a word (sometimes after that prior word has been conjugated) and can itself be conjugated. For example, たい as in 行きたい is also a 助動詞 even though たい is clearly not a verb in the traditional sense.
I mean, relative to how we learn grammar and how things are designated in Japanese, 如き behaves like one of the Classical Japanese ancestors of い-adjectives today, and those are just 形容詞, which we usually translate as ‘adjectives’. But 如き usually can’t function alone, so it’s an auxiliary word, and its classification in Japanese is indeed 助動詞. Even ない is technically a 助動詞.
It seems like it works with or without the の. I think I’ve seen the version with の more often though.
Based on dictionary definitions, っぽい (which should be transformed into っぽく in this case so it can act as an adverb) is more about showing a certain tendency or very much giving a certain feeling. みたい, at least in this usage, is more about resembling something in general appearance or shape.
(I didn’t bother copying the definition/meaning explanation because I think most people would have come across it shortly after starting to study Japanese grammar. Also, I swapped an active form for a passive form, and translated technical terms with their most intuitive equivalents, not conventional technical equivalents in English, so sorry if anyone feels I’ve been imprecise.)
You can basically attach it to any of the usual parts of speech in Japanese, as long as you use the right form.
Yeah, that’s the same general idea, just conjugating た・だ instead of the verb itself (see below). Generally speaking there are two conjugations in the 未然形 form, one that allows for negations (e.g. 行か・ない) and one that allows volition (e.g. 行こ・う) or supposition (e.g. であろ・う). By going the volition/supposition conjugation route (for godan verbs like above that means the オ conjugation instead of the ア conjugation), you can append the 助動詞 う・よう (う for godan verbs) to actually get the volition/supposition. (助動詞 is often translated as “auxiliary verb”, but it’s not always a verb in the traditional sense.)
Many parts of speech can be conjugated into the 未然形 and then have う・よう appended to get supposition specifically. You’re probably most familiar with だろう, where だろ is the 未然形 of だ, but as you just noted, there’s also the 助動詞 た・だ that gives past tense, where たろ・だろ is its 未然形, or 形容詞 like 暑い, where かろ is its 未然形 resulting in 暑かろう.