(Edited after Duolingo translation was changed from I sail tomorrow to I will be sailing tomorrow.)
Technically it is the future continuous tense - 'I will be sailing', so it should refer to some continuous action, such as sailing for three hours tomorrow. But in practice there will always be some leeway, just as with the English 'I will be sailing' which could also mean that I will be setting sail tomorrow.
Their translation of I will be sailing tomorrow is the best.
Also note that without the 'tomorrow' it could refer to a habitual action - 'I sail every day', but clearly the 'tomorrow' precludes that.
Thanks very much- I think I put in 'I will be going sailing tomorrow' which was rejected but it sounds like what they are going for as an English phrase. (obviously they can't get all possible versions)
'I sail tomorrow.' sounds more like something from a WWII movie, rather than going out in a boat.
A-màireach It is a feature of some dialects (Lewis I think) that slender r is pronounced somewhat like th in English the. This means that in this dialect you can tell the difference between slender and broad r, which you can't normally. So when you heard this word here you knew it was a-màireach, not
a-màrach. Very helpful with oirre 'on her' and orra 'on them' which are normally almost impossible to distinguish.
Chd was originally written and pronounced cht. It still is in Irish. You will have seen that using voiced letters where they sound unvoiced (and are written unvoiced in other languages) is quite common
Sgoil vs. Irish scoil vs. English school
but why it changed to sound like chk (as in Loch Katrine) I have no idea.
Edited: Yes, your sentence is grammatically correct, but is it the correct translation? This 'Bidh + vn' construction in Gaelic has two main meanings, the future continuous ('I will be sailing') and the present habitual ('I sail (every day)', so 'I will sail' does not really fit in here. It is really the translation of the simple future in Gaelic, seòlaidh mi.
There is always going to be some flexibility. I would say it is borderline whether they should accept yours so I don't think we can complain if they do or don't. And we don't know if they do, now that they have edited the answer after your comment.
This discussion has got very confused because people complained so they changed the answer.
If you mean "why isn't this present?" the answer is because bidh is future.
But if you mean "why can't I use the present with a future meaning?" the answer is partly that this is somewhat old-fashioned English, not generally accepted as contemporary colloquial English. Of course some people will use it, but there is a further, overriding issue, in that the bidh makes this either future continuous or present habitual (ruled out by the tomorrow). This means that it must mean 'we will be doing some sailing tomorrow', not 'we (will) set sail tomorrow', and this meaning is not covered by we sail tomorrow.
I agree that there is some overlap between I will be sailing tomorrow and I sail tomorrow, but only in the set sail sense, which is not possible with bidh.
(Note that I edited this after seeing DebF26's reply, which is why that may no longer make much sense.)
Yes it is a legitimate, if somewhat old-fashioned thing to say. Because of all the confusion, my comment missed the main point (that is covered elsewhere on the page) and so I have now edited it. It is a legitimate thing to say, but it is not a correct translation of the sentence in this question with bidh.
Well I'm over 50 but I'm not a sailor and I have never been on any journey longer than a ferry crossing. That may make a difference? But the second point about having to make it clear you understand this is future (whereas without the a-màireach this could be habitual present) stands whatever your view of what is or is not current.
Edited: They have now changed the answer (after your post) and they accept I will be...
By the context. This sentence is clearly non-habitual (because of the 'tomorrow'). In any language you get situations where you need to rely on context. In English, if I said I was sailing it could easily be past habitual - if I was sailing every day - or imperfect - if I was sailing yesterday.
Note that all grammar books I've read say that this 'bidh + vn' construction can be translated as present continuous, I sail (every day). Clearly in an appropriate context you could also use the future continuous that you mention, I will be sailing (every day next week).