Today in French class, we learned the following:

In both French and English, one says "If I am sick, I will drink tea," meaning "if in the future I become sick, I will drink tea." However, while in English one says "When I am sick, I will drink tea," in French one says "When I will be sick, I will drink tea."

This made me wonder about how these phrases would be translated into Esperanto. My best guess is that the future tense would be used for both.

"Se mi estos malsana, mi trinkos teon."
and
"Kiam mi estos malsana, mi trinkos teon."
Of course there is also the conditional:
"Se mi estus malsana, mi trinkus teon."

Usually learning things in French class make me worry too much about how to speak properly in Esperanto, but sometimes it also reveals my lack of a rigorous understanding of Esperanto.

Someone already asked this once:
se mi povos / se mi povas

Seth442:"Se mi estos malsana, mi trinkos teon."
"Kiam mi estos malsana, mi trinkos teon."
"Se mi estus malsana, mi trinkus teon."

I think your suggestions could all be fine, depending on the meaning you intend to convey. Esperanto is meant to make things easier, not harder. So concentrate on the intended meaning and translate it as simply as possible.

I have to say I've never used that construction in English before

(I'd say: "When I'm sick I drink tea/If I'm sick I'd drink tea").

Normally I'd say it's just:

"Se mi estus malsana, mi trinkus teon"
(I believe in normal Esperanto spoken by 100% of people, you use the conditional on the part of the sentence with "se" as well. There may be some cases where it's not necessary, but be safe and use the conditional with verbs hanging out with a "se" I think)

and

"Kiam mi estas/estus malsana, mi trinkas/trinkus teon"
(Roughly same deal as above).

Ultimately, you don't want to rely on English's somewhat irregular way of dealing with these tenses, it's easier to think "using Esperanto words, how can I saw what I need without over thinking" (until you're at the right stage for that). In most cases, if it's got a sort of condition in the sentence, use the conditional to be safe, as I assume that's what everyone else does.

That all said look at darkweasel's link because it deals with non -us phrases and "se", which are useful.
E.g.

Tommjames (translated):You can see that both forms are used, but they have different meanings.

Mi venos se mi povos means that I will come, if I can in the future.

Mi venos se mi povas means that I will come, if I can do so now.

So, it depends. If you're speaking purely hypothetical, I reckon use -us with verbs, but if you are planning or saying factually what you can do or do if something happens, rather than what would happen as a general statement, there's the other verb endings to consider.

But for your example I'd say "Se mi estus malsana, mi trinkus teon" (If I were sick, I'd drink tea).

Seth442:
"Se mi estos malsana, mi trinkos teon."
"Kiam mi estos malsana, mi trinkos teon."
"Se mi estus malsana, mi trinkus teon."

All three of these are correct sentences:

Se mi estos malsana, mi trinkos teon.= If I am sick (at some time in the future), I will drink tea.

Kiam mi estos malsana, mi trinkos teon.= When I am sick (in the future), I will drink tea.

Se mi estus malsana, mi trinkus teon.= If I were sick, I would drink tea.

It's just a matter of which of these ideas you want to express.

Mustelvulpo, those were the exact translations that I intended.

I'm pretty sure I understand this from at least an intuitive standpoint now. The basic idea seems to be that "os" is used to express that something will occur in the future, and that it doesn't necessarily get used in the same situations that that the simple future tense would be used in English, or in French, etc.

As I said, French class always makes me worry about speaking Esperanto. I guess it is because French is so rigid and illogical that when I see how something has to be said in French it makes me worry that the much easier and more sensible way of saying things in Esperanto might be wrong. I feel like I have a reasonable ability to write fluidly in Esperanto, whereas in French I'm lucky if I can write a formulaic sentence correctly.

Seth442: The basic idea seems to be that "os" is used to express that something will occur in the future, and that it doesn't necessarily get used in the same situations that that the simple future tense would be used in English, or in French, etc.

As I said, French class always makes me worry about speaking Esperanto. I guess it is because French is so rigid and illogical that when I see how something has to be said in French it makes me worry that the much easier and more sensible way of saying things in Esperanto might be wrong.

Yes, -os is always used to express something in the future, which is sometimes different from English. For example we might say- "Tomorrow is Wednesday." (present tense). In Esperanto you should always say "Morgaŭ estos merkredo-" (not "estas"). Really, the Esperanto way makes more sense. After all, tomorrow IS in the future.

I know what you mean about French. I studied it in high school and college for six years. I can still pick up a book in French and read it, but I have a hard time discussing anything more complicated than the weather. There's a big difference between recognizing words when you see them and remembering them when you need to say them.

Unlike with many languages, when you have a pretty good basic knowledge of Esperanto, you'll find that your instict on how to express any particular idea will be right the vast majority of the time and, even if you make a minor error, you will usually still be understood. (e.g.- "Morgaŭ estas merkredo" would be understoood with no problem)That's the beauty of the language!

Nobody:November 2003 10:27
Englsih does not have a future tense in the strict sense of the word. Unlike other languages, there is no verb form that indicates future meaning (in the same way thet '-ed' indicates the past tense. rather there are 12 or so forms of construction to indicate the future - from the use of the auxiliaries 'will' or 'going to', to the the present simple or continuous with a future time adverb - such as 'tomorrow, next week, ...'.

willbut - 7th December 2003 14:07
We can talk about future time easily enough, but I'd say we use the present tense to do that, and also the past tense for unlikely or imaginary futures.

grahamcurrie - 10th February 2004 00:56
There is no clear answer to this question because there is no universal definition of "tense".If regarded as purely about verb inflexions, there is only one tense in English. If the adding of auxilliary verbs constitutes a tense, then there are many, including a future tense.

jorge - 16th August 2006 21:49
English has only 4 definite tenses: Simple present and past tenses plus Simple present and past perfect tenses and those that derive from them.if you feel like calling them tenses, be my guest. I won't count them. The rest are modal verbs.

Copied from an English discussion site. Since EN doesn't have a proper future tense, do not worry about saying/translating this wrong.