Translation:Six fish are swimming in the pond.
Both are plural forms but they have differing uses. Fish refers to several individual fish, especially of the same species, while fishes refers to several species of fish and is usually used now only in biological contexts.
Both should be acceptable as far as I can tell, but fishes currently isn't. It is the historical plural form and can still be seen used as fish is sometimes, so it certainly isn't wrong.
I agree that it's generally implied in English, but the same sentence could mean the fish are stationary (asleep or dead or made of plastic). To say the fish are "swimming" further implies movement, so I think it's neither incorrect or a tautology.
Also, this is all just a learning exercise, so when I said "your answer needs to include "are swimming" ", I didn't mean that it's the only way one can refer to six fish in a pond. The course creators probably wanted to avoid confusion between います ("to be") and 泳いでいます ("to be swimming") by only accepting answers which include "swimming", not to say that answers without it are invalid translations.
「で」particle is not only intended for that purpose but, among others, it is also a location-related particle. So, the question of stvern6 seems very reasonable. As for me, if I had had to construct the sentence from scratch I would have probably used 「で」particle. Nonetheless I also find natural to read it with 「に」.
It would be nice if someone with a more advanced level of Japanese grammar could shed some light and tell whether both options are correct or not, and if the positive is true, if there is any nuance or difference in meanings.
I'm not a grammar expert, but I'll give it a shot :)
I believe the reasoning behind this relies on the fact that 泳いでいます (およいでいます) can be used for both present progressive tense and present perfect tense. This is usually clarified by the context; for example:
- 今は、泳いでいます (いまは、およいでいます) = "I am swimming now."
- 長い間泳いでいます (ながいあいだおよいでいます) = "I have been swimming for a long time."
The first sentence is plain old present progressive tense, since all we know is that the action of "swim" is currently happening. However, in the second sentence, the action of "swim" occurred in the past, but is continuing in the present, therefore it is present perfect tense. Technically, present progressive is a sentence describing an action, while present perfect is describing a state of being as a result of an action in the past ("I have been swimming for a long time" = "I am now in the state of having swum for a long time in the past").
As you can see, both of these tenses use the same conjugation in Japanese, but the tense is still preserved through the context. As a result, the particles can also change to reflect the difference of action vs state. で is the particle for indicating the location where an action occurs, whereas に is the particle for indicating the target location of an action (i.e. the location of the end result of the action).
So, hopefully it makes sense that while the English translation of 池にさかなが泳いでいます is "Fish are swimming in the pond" (i.e. present progressive tense), the Japanese sentence is more like "The fish are in the state of having been swimming in the pond (since the past)." Side-note: We can't simply translate it to "Fish have been swimming in the pond" since that has ambiguities in English which don't correlate to the Japanese sentence, namely describing past experience.
On the other hand, in the case of the girl, it is much more likely that the sentence we would use is for describing what she is currently doing, not that she has always been swimming. Therefore, 女の子が池で泳いでいます is appropriate because で indicates where she is currently swimming.
Hopefully that make sense, and hopefully I haven't made any mistakes in my understanding of these particles. Honestly though, I think this type of question is the kind that even native speakers may have trouble articulating, since they wouldn't normally think about the why.
Both. ひき is the "base" form; it can sometimes become びき or ぴき when it's the second part of a compound word. The former process (ひ becoming び) is known as rendaku; the latter seems to have a more interesting explanation. Apparently the Japanese phoneme /h/ was historically actually /p/.
This comment on a Language Log post contains an explanation (albeit a slightly technical one) after someone asked how 鉄（てつ） and 坂（はん） combined to make 鉄板（てっぱん）.
(Note that the romanization system used by the commenter isn't Hepburn romanization, the most commonly used one nowadays.)
"The part you’ve explicitly asked about is in bold script. You can see, I think, that what you’re dealing with is a common and regular feature of Japanese, and one that has resulted from the historical change p h at the beginning of a word (or, in the case of Sino-Japanese, of a morpheme). (I might add parenthetically that a /p/ in Old Japanese occurring in medial, intervocalic position was different; there it developed into -w-, and that’s the source of the irregular conjugation of, for example, kau ‘to buy’, so that you get, e.g., kaimasu but a /w/ in kawanai. You probably already know these things, but I thought I’d pass them along anyway, just in case.)
Many different processes relate h with p.
(1) Sino-Japanese compounds. If the Sino-Japanese pronunciation (the on reading) of a Chinese character begins with h, that h will become p following the mora nasal, or tu or ti; thus iti ‘one’ + hun ‘minute’ gives ip-pun. (The tu or ti becomes a mora consonant.)
-hun ‘minute’ ip-pun ‘one minute’ san-pun ‘three minutes’
-hatu ‘departure’ syuppatu ‘depart’ (syutu + hatu)
hookoku ‘report’ koohoo ‘official report’ denpoo ‘telegram’
(2) Intensification. Some words can be pronounced emphatically by doubling a medial consonant. Thus totemo pronounced emphatically is tottemo; amari becomes anmari. But if the medial consonant that is doubled is h, the h becomes p:
— karappeta (from kara ‘empty’ + heta ‘unskilled’)
(3) The intensive prefix ma(t)-. This prefix turns kuroi ‘black’ into makkuroi ‘jet black’; siroi ‘white’ into massiroi ‘snow white’; taira ‘flat’ into mattaira; etc. When it is combined with words that begin an h, it changes the h into p.
mapputatu ‘just exactly in two’ (hutatu ‘two’)
mappadaka ‘stark naked’ (hadaka ‘naked’)
mappiruma ‘broad daylight’ (hiruma ‘daytime’)
(4) The prefix ko(t)- ‘small’.
koppidoku ‘a little harshly’ (hidoku ‘harshly’)
(5) Related words.
ha ‘leaf’ happa ‘leaf’ (colloquial)
hayai ‘quick’ kenkappayai ‘quick to quarrel’ (kenka ‘quarrel’)
hiroi ‘wide’ dadappiroi ‘unduly wide’
hana ‘nose’ sisippana ~ sisibana ‘pug nose’
hara ‘stomach’ karappara, sukippara ‘empty stomach’
— yoppite ‘all night long’ (from yoppitoi, which is said to be from yo hito-yo ‘one night of night’
hikaru ‘shine’ pika-pika hikaru ‘flashes with a flash’
Phrases like omo ni miru ‘see (as) important’ contract to omonmiru ‘reflect carefully’, and omo ni suru ‘make important’ to omonziru ‘honor, respect’. In the same way, omo ni hakaru ‘estimate (as) important’ contracts to omonpakaru ‘consider’.
More examples of verbal contractions:
hiki- ‘pull’ + haru ‘stretch’ → hipparu ‘pull’
hagu ‘strip off’ → hippagu ‘strip’
hataku ‘slap’→ hippataku ‘slap’
oi- ‘shoo away’ + hazimeru ‘begin’ → oppazimeru ‘begin’
- hooridasu ‘throw out’ → opporidasu ‘throw out’
yoi- ‘get drunk’ + harau ‘clear away’ → yopparau ‘get drunk’
(7) The suffix -ppanasi ‘(leaving something) just as it is’. This suffix is derived from the verbal forms hanasi ‘leaving it’.
tuke-ppanasi ‘leave turned on’
ake-ppanasi ‘leave open’
koware-ppanasi ‘leave unrepaired’
oki-ppanasi ‘leave lying somewhere’
tati-ppanasi ‘remain standing’
(hon o) kari-ppanasi ‘(books are) unreturned’"
This other page gives a much shorter explanation of when /h/ becomes /p/.
"The ha, hi, fu, he, ho (はひふへほ and ハヒフヘホ) sounds were originally pa, pi, pu, pe, po, sounds which are today indicated by a circle handaku diacritic (ぽぴぷぺぽ、パピプペポ). The sounds shifted as a result of a process linguists call bilabial dissimilation, enabling modern speakers of foreign languages to marvel at how it's possible for many Japanese to speak with a minimum of mouth movement.
In modern standard Japanese, the unvoiced pa, pi, pu, pe, po handaku pronunciations occur in these cases:
Following a nasal n ん, except after "four"よん
Sokuon and Handaku: In kanji compounds, after a kanji whose the pronunciation ends in ち or つ, and the following consonant is not voiced, the ち or つ are dropped and the lengthening of the following handaku consonant is indicated by a writing small tsu (っ)."
I really suggest you to look at allophones and phonemes in general. It's not a random choice of which sound to use. It depends on the sound environment (the sound of the word before and/or after it). For now, you just need to remember this: http://www.punipunijapan.com/counting-small-animals/
It does matter. You use ひき びき or ぴき for live small to medium animals except for birds, rabbits (long story), and some others.
The sound depends on which number precedes the counter. For example, only 3 gets followed by びき: 三匹 さんびき. The others are either ひき or ぴき depending on the number before them.
I prefer tofugo to punipuni. This has a very detailed explanation of which counter to use when and with what. It includes kanji, hiragana, and most importantly, you can hear how each counter is pronounced correctly.
ひき/匹 is fine for fish. So is こん, but it is arguably archaic and less used. So much so that I can't even get my computer to come up with 喉 without typing のど instead...