German has many such examples since the last major spelling reform of the 1990s. It wasn’t a complete overhaul, but some spelling rules were changed which affected a lot of words - most importantly, in many (but not all) instances the particular German character ß became ss. Both old and reformed spelling are considered correct; newspapers typically have their own house style that prescribes which of the two to follow, and individuals just follow their personal preference.
@Schnitte (or @EinsteinsHund ), are there any words borrowed into German that ended in -c or -que in their original languages, but can be properly spelled with either -c/-que or -ck in German?
I checked two with English just to see: English “shellac” is German Shellack, English “lilac” is German lila. So that’s a no, and another no.
It was apparently common up into the 40s, but I still see it pop up on occasion.
An example I can think of is the adjective chic, which I’ve seen both in that spelling and in its Germanised form schick.
Two examples of alternative spellings introduced by the spelling reform not including “ss/ß” are “Delfin” for “Delphin” (you guessed it, dolphin in English) and “Portmonee” for “Portemonnaie” (a loan word from French for purse), which I find exceptionally ugly and illogical.
ETA, as an aside: the old spelling of the word for valley was “Thal”. This changed sometimes in the 19th century to “Tal”, which still is the correct spelling. When fossils of a different kind of human than us were found in the neander valley near Düsseldorf, the species was called after the excavation site “Neanderthaler”, which the English speaking world adapted as “neanderthals”. Since then, the German spelling reformed to “Neandertaler”, while English speakers have kept the additional ‘h’.
Had you checked French laque (laquer) you woud have gotten German Lack. So yes.
Are Lack and Laque both acceptable alternate spellings for the same word in modern German, though?
No, they are not. Only Lack is correct. Seems I misread your question.
- Ambience is the character and mood of a place.
- Ambiance is an alternative spelling of the same word.
Are alternate and alternative two correct spellings of the same word or two different words with different meanings?
Both can be nouns, but they seem to me to have different noun meanings.
“alternate” used as a noun can mean a person’s deputy or acting person: “While you’re away, who is your alternate?”
“alternative” used as a noun can mean a plan or option: “If your preferred plan can’t be done, what’s your alternative?”
Both of those are adjectives doing work as nouns.
No – different pronunciations with the latter having an extra syllable.
… or two different words with different meanings?
Different words with different – but overlapping – ranges of meaning. Both can be either noun or adjective, and somehow they’re not frequently interchangeable as a matter of style (though usually understandable if a non-native substitution is made).
The alternate juror is waiting in the hallway. (Acceptable)
The alternative juror is waiting in the hallway. (Grammatical, but odd. The listener would wonder what the heck you meant by ‘alternative’ … or just assume you flubbed and meant ‘alternate’)
While a brick cantilever won’t work, a molded cantilever would be an alternate solution. (Acceptable)
While a brick cantilever won’t work, a molded cantilever would be an alternative solution. (Acceptable)
I’ve thought this through and considered the alternatives. (Acceptable)
I’ve thought this through and considered the alternates. (Grammatical, but different in connotation. Void of context, this sentence strongly implies that the alternates are people as opposed to plans, ideas, etc.)
…
On top of that, “alternate” can be a verb. “Alternative” could only be a verb in a nonce usage.
You should alternate hands when painting a fence to avoid fatigue. (Acceptable)
*You should alternative hands when painting a fence to avoid fatigue. (Ungrammatical)
“Alternate” also has a verb meaning that “alternative” doesn’t have:
“I want people from Table A and Table B to alternate as they come forward.”
ETA: ninja’d while I was thinking of a verb example!
Ah, this again. OK, how about we change the official spelling of a few more wourds for the sake of consistency. 
Here are a few free samples!
motor → motour
rotor → rotour
sector → sectour
Thank you. And to @bordelond. TIL.
Canadian "U"s have proper posture.
Our "u"s are so droopy they’re on the floor - the cutting room floor. 
Sort like classic Southern drawly accents. If they was any lazier, they’d be nappin’ on the porch.
I have seen ailloli with only one l, but not with two.
There is also “cuiller” and “cuillière” (spoon)
and “clé” and “clef” (key)
In some cases, English has valid variants within a single dialect - for example in the case of British English, a number of the ~ise/~ize words are valid either way.