Near as I can tell from the Valyrian language wiki, it consists of the noun “man” in the collective and the verb “die” in the present active infinite. Essentially, “men collectively (to/do) die.” I do not understand where the “must” part comes in, but the analytical English is my mother tongue so the subtlety of a clearly Latin-inspired inflectional language is lost on me.
Yes, valar morghūlis does mean ‘all men must die’.
TheLethalCarrot’s answer gives most of the background of High Valyrian, but unfortunately misparses some of the grammar of the sentence, which results in a misunderstanding of how and why the phrase means what it means. The same misunderstanding also rears its head in Mithrandir24601’s answer. This is going to be an awfully long answer to describe the grammar in detail and explain exactly why valar morghūlis does mean ‘all men must die’.
There are two essential things to understand in the phrase:
1. Valar is not plural, but collective
High Valyrian nouns have four numbers: apart from singular (one X) and plural (several Xes), it also has collective (a lot of Xes, all Xes) and paucal (a few Xes, some Xes).
The word meaning ‘man’ is the lunar noun vala, which has the plural vali, paucal valun, and collective valar (in the nominative case).
Valar is thus the collective form, and it does in fact mean ‘all men’ or ‘a great host of men’, or ‘mankind’ (as opposed to ‘womankind’)—it’s the form that sees all men as a single entity.
This ‘single entity’ bit is important. Unlike nouns, verbs and adjectives have only two numbers: singular and plural (like English); there are no collective or paucal verb or adjective forms. Instead, paucal nouns take plural endings, and collective nouns take singular endings. Because the collection of all mankind is seen as a singular entity, it counts as a form of singular.
2. Morghūlis is not present, but aorist
The table that TheLethalCarrot cites in his answer shows that morghūlis is the third person plural form of morghūljagon in the present indicative active—which is true. It is. But as we’ve just seen, a collective noun counts as a singular and should take a singular form, not a plural form. So valar cannot be the subject of morghūlis—that would be like saying “a man die” or “all men dies” in English.
Luckily, if we take another look at the verbal conjugation tables, more specifically at the aorist aspect-tense further down on the page, a solution presents itself. Morghūljagon is a consonant-final verb (the L is the end of the root), so it conjugates like jaelagon in the table. This means the third person singular (which is what we are looking for) ends in -is in the aorist indicative active: morghūlis. Perfect.
So the phrase valar morghūlis is a collective, aorist phrase.
Present, aorist… what’s the difference?
What the actual difference is between the present and the aorist is something that requires some extra knowledge and describing.
If you take a look at the time and aspect table at the top of the verb conjugation page, you’ll see that High Valyrian verb forms can be interpreted as encoding two separate notions: time and aspect. The present and the aorist are both under the ‘Basic Aspect’, but in different time categories.
The concepts of time and aspect both require some introduction, because they’re not necessarily very intuitive if you’re not a linguist, and different languages often treat them in different ways.
Time is simple enough, really: as far as High Valyrian (and English, mostly) goes, it’s essentially past, present, future, and indeterminate. That is, you can explicitly mark that an action took place in the past, takes place in the present, or will take place in the future—or you can leave out the time information altogether, making it context-dependent or just plain uncertain when the action took/takes/will take place. The first three exist in English; the last one doesn’t as a separate category. To express something timeless, we just use the simple present in English (“The earth is round”, “The universe is huge”, etc.—those things are true in the present, but also in the past and future). In High Valyrian, however, they are distinct categories, so there are explicit ways to say that something does not relate to time, but is either universally true or just time-agnostic.
Aspect is more complex and vague: it’s a concept that describes “the way in which time is denoted by a verb” (ODO, sense 3); that is, different ways of looking at a particular time. For example, the present time can be looked at from various aspectual angles, such as:
- basic/default aspect (something that occurs in the present time, with no emphasis on anything else: “I feel sick”)
- progressive/continuous aspect (something that is currently ongoing: “I am feeling sick”, “I am writing a letter”)
- habitual aspect (something that tends to be in a certain way regularly or out of habit: “I feel sick on Saturday mornings”)
- universal aspect (something that is always true: “The universe is huge”). We’d consider this an aspect of presentness in English, but in High Valyrian it wouldn’t be
- resultative aspect (something that is so in the present, but is the result of something happened in the past: “I have eaten two hamburgers”)
So what does that mean?
In English, the simple present tense tends to actually denote the habitual or universal aspects for most verbs (“I drive a car”, “I eat breakfast”, “I like tea”), while the basic or default aspect tends to merge with the progressive aspect: if we want to say that the statement ⟨drive a car⟩ is something which occurs in the present moment with me as the actor/subject, we have to use the present continuous construction, “I am driving a car”. This is not true for all verbs, though: some verbs distinguish the basic and the progressive aspects quite well. “I am at school” is basic aspect (it just deals with a singular, current moment in time and describes it), whereas “You’re being an idiot” is progressive (it emphasises that the idiocy is something that is currently ongoing, not just a moment-in-time snapshot).
You could say that the English present tense most commonly combines present time with either habitual aspect or universal aspect, and only sometimes with basic aspect. The present progressive combines present time with either progressive aspect or basic aspect.
In High Valyrian, on the other hand, present tense only combines present time with basic aspect, describing things that are happening right this instance. It doesn’t emphasise that they are currently progressing or ongoing, but it also is not used for habitual or universal statements.
The High Valyrian form that combines present time with habitual aspect or universal aspect is instead the aorist.
The universal aspect often carries with it overtones of finality, inevitability: if something is universally and timelessly true, it is inescapable. The advent of death is universally true—past, present, and future. It is inescapable. This adds a layer of modality to the statement, which in English is often expressed through the use of modal verbs. In the English translation “All men must die”, the modal verb must is used, which has two basic meanings:
- a deontic sense: ‘be obliged or duty-bound to’ (“I must go”, “You must try this sponge cake”)
- an epistemic sense: ‘be logically or alethically unavoidable’
Clearly, in the translation, the second meaning of must is used. It doesn’t really mean much in itself, but it emphasises that the statement is known to be unavoidably true. Leaving out the modal verb altogether would create a sentence in the simple present tense, “all men die”, which would still encode universal aspect and thus mean pretty much the same thing, just without stressing the inevitability quite as explicitly.
With all that, we end up with a situation that reflects pretty much exactly what ‘Mad Latinist’ (see TheLethalCarrot’s answer for the actual quote) says:
Valar morghūlis is an aorist statement. The aorist combines timeless aspect with present time and is used to describe universal truths. Universal truths tend to have nuances of epistemic unavoidableness, which is frequently made explicit in English by adding the verb must. Thus, “All men must die” is a perfectly valid and literal English translation of High Valyrian Valar morghūlis.
It likely doesn't, at least not properly. George R. R. Martin has said several times he only creates words as he needs them and is no linguist. In fact the actual language itself is only a handful of words.
[How developed is Valyrian?]
"How little" have I developed Valyrian is the real question. I am not, alas, J.R.R. Tolkien, and I cannot imagine taking a decade to actually work up not one, but two, entire languages. I have something like eight words of Valyrian. When I need a ninth, I'll make one up.
Sorry if that disillusions any of you. It's all smoke and mirrors, kids.
In fact the actual main development of the language was done by David J. Peterson when working for Game of Thrones. George has even appeared to defer the language creation to Peterson so he can get it "right".
Then he recounted the anecdote -- which he's recounted before -- of someone mistaking him for a Tolkien type and wanting his grammar and glossary and the like of Valyrian, and George admitting that Valyrian was seven words, and when he needs an eighth he'll make it then.
Of course, he then added that with HBO having created Dothraki through the work of David J. Peterson, he feels like now if he wants to have Dothraki (and Valyrian as well) he'll have to refer to Peterson's work to get it "right", or ask Peterson himself how to say something in Dothraki.
Peterson then used "Valar morghulis" and "Valar dohaeris" as the basis for much of the language creation so had little to go on.
Since I've already talked about Dothraki, let me address Valyrian specifically. I designed a bit of the case system and almost the entire verb conjugation system just using Valar morghulis and Valar dohaeris. Bless GRRM for using an -is suffix on both. After that, it was just nouns and names, which proved useful for sussing out the phonology and helping to define declension classes.
It's the collective. Thus: vala "man"; vali "men"; valun "some men"; valar "all men".
Reddit, r/IAmA, Eseneziri! I'm David Peterson, the creator of the Dothraki and High Valyrian languages for HBO's Game of Thrones, and the alien language and culture consultant for Syfy's Defiance. AMA
This answer is mainly to point out that the language was never initially developed properly so it will have flaws and the one you've found is a potential one.
As pointed out in the answer by @Janus Bahs Jacquet my answer contains some misunderstandings of how the language is formed. Be sure to read that answer for a better explanation on the language.
However, as far as I can tell your translation seems pretty spot on. From the above quote we can see that "Valar" means "All men" and from the languages wiki we see that "morghulis" means "to die".
So the literal translation is essentially "All men (to) die". However, according to "Mad Latinist", a user on the Dothraki forum, it can be translated to "All men must die" because the phrase is implying something can always be true though the main translation of the phrase appears to be "All men die".
This is also the verb form in the infamous Valar Morghūlis/Dohaeris, conventionally glossed "All men must die/serve." Because the aorist implies something is always true, it can sometimes be translated with "must," especially when used with a collective noun. Let's play with that a bit:
- Valar morghūlis (col, aor) "All men (must) die."
- Valar morghūljas (col, pres) "All men are dying."
- Vala morghūlis (sing, aor) "A man dies."
- Vala morghūljas (sing, pres) "A man is dying."
Many languages have words that are implied when omitted. This happens everywhere in Japanese.
Consider the English sentence "Come." As with all commands, the subject "you" is omitted but we all understand that the speaker means for you to come. Where are you coming to? That's also omitted and therefore implied. It's either "come here" or "come with me" or something like that.
In some other language, especially a fictional language, it's easy to imagine that the concept behind the word "must" could be implied without being stated explicitly. And in the cultural context of the language, there may be no distinction between "this is" and "this must be."
The usual disclaimer/piece of real-world context is that GRRM has just made whatever words he wants up as and when he wants to1, as mentioned in TheLethalCarrot's answer.
As already mentioned in the question, the literal translation of Valar is "[the collective of, meaning 'all'] men". Morghulis is a tad harder, but it starts with "morghūljagon" being the verb "to die", or rather "entering/going [-jagon] towards the state [-ūljagon, which is inchoative] of being dead [morghe-]" (i.e. 'becoming dead'). The only 3rd person plural form of this with the ending '-is' is indeed the active present tense (which, we're told, is not used for timeless actions or general truths).
And so, the most literal way of translating this is along the lines of "[the collective of] all men are [currently in the process of] entering the state of being dead". This is somewhat clunky, so if we want to translate this in a more useful way, "all men are dying" or "all men are becoming dead" are easier to work with, without loosing any of the meaning of the Valyrian. Of course, if all men are dying, then this is the same thing as saying that "all men must die", even though it doesn't literally translate to be the same, word-for-word and does indeed loose much of the subtlety of the Valyrian language.
In other words, this all boils down to the subtleties of translation, the meaning of the word 'must' meaning the it definitely will happen, so the process (in this case) has already started and that George R. R. Martin just isn't a linguist and David J. Peterson did the best he could with what he had.
Edit: As Janus Bahs Jacquet said, because 'Valar' is a collective, morghūljagon takes the singular verb suffix and hence, is aortist. This essentially makes it a statement of fact that 'all men undergo death', which, as pointed out by Janus Bahs Jacquet, is often stated in English by using the word 'must', hence 'all must must die'
1 This is past tense, as he would now go to David J. Peterson if he needs new words/phrases