"I do not want to swim in the sea in winter."
泳ぎたい (およぎたい) means "(I) want to swim". When made into negative form, たい becomes たくない (plain form) or たくありません (more polite) 泳ぎたくない (およぎたくない）and 泳ぎたくありません (およぎたくありません) both mean "(I) do not want to swim" The subject is determined by context or indicated by particles. "I" applies in this specific example.
Yes, that's basically correct. However, the conjugation changes slightly. -たく is the negative form of the -たい conjugation that indicates desire.
ふゆに うみで およぎ ありません is NOT a properly conjugated sentence.
If you're talking about a factual statement involving the verb, there are various statements you could use depending on the politeness or formality required.
The subject (I, he, she, you, whatever) depends on context - I will use "I" below to match the sentence people are commenting on from Duolingo.
冬に海で泳ぎません。 ふゆに うみで およぎません。 I do not swim in the sea in winter. (semi-polite)
冬に海で泳がない。 ふゆに うみで およがない。 I do not swim in the sea in winter. (not polite, casual)
You can further change politeness using keigo variants:
冬に海でお泳ぎになりません。 ふゆに うみで お およぎ に なりません。 (You) don't swim in the sea in winter. (speaking about someone else, elevates their rank compared to you)
冬に海でお泳ぎしません。 ふゆに うみで お およぎ しません。 I do not swim in the sea in winter. (speaking about you, humbles yourself compared to the speaker.)
You should notice a number of fairly logical commonalities between these conjugations - Japanese is fairly regular and logical about how things are conjugated, but there are a number of irregular things, too.
Hope that helps.
冬 is "winter". The hiragana here are "particles" they serve a grammatical purpose. 冬は indicates that winter is the subject of the sentence (e.g., 冬は来る for "Winter is coming"). 冬に means "in winter" , not just winter. The particle に is used for "in" when it relates to time. It is also used to indicate the destination "to" in direction lessons (covered later) but would not be used for "in" the sea.
冬は and 冬に are not equivalent. This is not a mistake (although DL could work on how they introduce Japanese grammar). Japanese frequently drops the subject (as the romance languages do), the subject will be assumed to be I/you/we/them unless specified so these are different sentences with different meanings:
冬は来る for "Winter is coming"
「私は」冬に来る for "[I'm] coming in Winter"
Sorry, I have may mixed up the particles は and が. This distinction still confuses me sometimes. They serve much more similar purposes than は and に. I hope this explanation (and the examples) are sufficient to show the difference between は and に (even if my terminology isn't "textbook").
In terms of SOV I think 冬は (or 冬が) is a "subject" and 冬に is an "object", although Western grammatical concepts do not map neatly to Japanese as you point out.
I think this issue comes from an ambiguous translation into English. I don't think this is an error in the Japanese but rather teething issues with teaching the grammatical differences.
冬に... is ..."in winter"
冬は... is "During winter..." when used in previous examples:
冬は寒いです would be "Winter is cold" or "During winter it is cold". Of course, the meaning (in this example) is equivalent to "It is cold in Winter" but the grammar is different and not appropriate for the above question.
Thank you for the kind attempt at more detailed explanation. I am aware of those details. My initial discussion comment was trying to highlight that under the right circumstances, either can be acceptable - due to what KiritsuguZFC points out.
「冬は海で泳ぎたくないです。」could be seen as something like "As for winter, [I] don't want to swim in the sea." The topic is winter, but the (unsaid) subject is yourself.
In prior lessons, sentences like「冬は学校に行きます」are translated as "I go to school in winter." (which is fine). When translating in reverse, many of these examples have not accepted the types of translations you suggest. (Hence this comment.)
While I have added individual suggestions for acceptable answers in the applicable questions, I also like to comment when it appears to be a more consistent issue across questions.
No, the ending -tai/-takunai is only used to express the speakers preference. It always means "I (don't) want to".
It would rather be something along the lines of "In the case of winter, I don't want to swim in the sea." (Or "Speaking of..." or "Regarding...") Not quite the same as "During...", which requires the ni (or ni wa).
umi: ume is plum :p
You're correct that 泳ぐ involves motion, and 海に泳ぐwould theoretically mean something like "swim to the ocean"...which doesn't make much sense though, which is why it's not really used (unless you're near the river mouth, but even then I think you'd say "海(の方)へ泳ぐ")
You can, however, say 海に泳ぎに行く (I'm going to the sea to swim)
Source (in Japanese unfortunately): https://sp.okwave.jp/qa/q6963432.html
「冬に海で泳ぎたくないです」is indeed an acceptable way to write "I do not want to swim in the sea in winter." Please add it as a suggested correct answer if you haven't already.
It seems like textbooks and teaching defaults to -くありません because it is more formal, but everyday teineigo uses -くないです far more frequently. Using ありません sounds overly formal. (I confirmed this reply as being generally correct with my native speaker friend.)
My friend cautions me that 泳ぎたくないです still sounds fairly 'strong' and forceful, despite using です to soften the 泳ぎたくない.
The general rule of thumb is to use に for time and for place of existance (e g before います and あります, but also 住んでいます and others), but use で for place of action. (There are some finer points and special cases, but that is the basic idea.)
Beyond that, に is also used to indicate movement (mostly "to, into", but also "from"), in which case it is comparable to へ and から, respectively, but で can not be used; to indicate the indirect object; to indicate the agent of a passive verb; and a few other ways. Similarily, で is used to indicate -- among other things -- implement, material and reason, none of which に can be used for.
Japanese verb conjugations change based on positive or negative use. This is an example of negative use conjugation.
公園へ行きたいです （こうえんへいきたいです）I want to go to the park 仕事へ行きたくないです （しごとへいきたくないです）I do not want to go to work.
Verb conjugations that express desire end in －たい -tai. When used in a negative fashion (don't want to), the －たい -tai turns into －たく -taku, and you add ない nai.
You see similar changes in ーい adjectives: 寒い samui - cold 寒くない samuku nai - not cold
The addition of です desu is a little more polite. 古いです furui desu - old (inanimate things) 古くないです furuku nai desu. - not old (inanimate things)
Hope that helps!
Pardon my simplification - I hope this explains a little.
に is used for time context (at five pm) and other things (direction, others). で is used for positional context for action (I swam in/at the pool) or identifying means by which something happens (I went by car)
公園で散歩しました I walked in the park, I took a walk in the park. 午後5時に食べる I (will) eat at 5pm. 車でと京へ行きました I went to Tokyo by car. 大阪に行きたい I want to go to Osaka. (へ can also be used in this instance - there are differences implied in choosing one particle over the other)
I believe fuyu requires a particle.
★ You don’t usually need the particle に ( = ni) with the followings time words because they already function as an adverb.
今 = ima = now
今日 = kyou = today
今朝 = kesa = this morning
今晩 = konban = tonight
今週 = konshuu = this week
今月 = kongetsu = this month
今年 = kotoshi = this year
明日 = ashita = tomorrow
明後日 = asatte = the day after tomorrow
来週 = raishuu = next week
再来週 = saraishuu = in two weeks
昨日 = kinou = yesterday
昨夜 = sakuya = last night
昨晩 = sakuban= last night
一昨日 = ototoi = the day before yesterday
去年 = kyonen = last year
一昨年 = ototoshi = two years ago
毎日 = mainichi = everyday
毎朝 = maiasa = every morning
毎晩 = maiban = every night
この間 = kono aida = the other day
先日 = senjitsu = the other day
It might not be a complete list, but seasons are not included.