So… Could you please tell me some phrases that indicate surprise, and also the severity of the outburst…
Generally it would come from single noun utterances (a single noun is a sentence in Primal). Here are some examples in phonetic script. (Keep in mind "khh" is a throaty h sound like Hugo, and "uo" is the oo in foot or the ou in could.)
(chaykhh) means "surprise" or "shock". This is the most common "Oh!" or "Yipe!" expression.
(pal) is something you say when you shout "surprise" in order to announce a surprise to someone else. It refers to a surprising event, like a surprise party.
(tsal) means "fear". This is the most common "I'm scared" expression, though generally when someone is truly frightened they'll just scream random vowels, like anyone in any language would.
(n'thung) is a weird one...this means "the present, repeated tense". It can be used to mean "again?" or "hmm?" if you missed something someone said. (A more direct request for repetition would be (z'thung-lee).)
(kur) is the question word. By itself, it's like saying "huh?" or "what?" or even, "could you clarify that?" or "what happened?"
(vuokhh) means "confusion". It's most like "what the hey...?"
(murng) means "happiness" and is often used as an expression of comfort.
(mur) means "pleasure". It's similar to murng, but a bit more emotional.
(wur) means "yes", and is often used to indicate concordance with things.
(rukhh) means "no", and is also often yelled when frightened or startled by something bad.
(ngef) means "fake thing". This can be used to express disbelief that something is genuine, such as thinking one must be dreaming.
(zeekhh) means "irritation" and is similar to "ow".
(pohldth) means "pain" and is similar to "Ow!" (dth means a voiced TH sound)
(wik) means "disgust" and is similar to "eww."
(chen) means "sentiment" and is similar to "aww..." when used in an adoring tone. (chen-kee) is the uber-cute version.
(wee muth) means "I fail" or "I err" and is similar to "aww..." when used in a "darn it" context. It can also mean "my bad" or "whoops".
(leezh) means "impossibility". This is used when something is very startling, but in context it can also mean, "how dare you!"
Note that these differ more based on context than on severity. More severe forms could be made by adopting -tsee at the end (so tsal-tsee means "very much fear"), with the exception of kur which generally doesn't take suffixes in this way. Or less extreme forms could take -khhee. But as exclamations, neither is common...it's usually just the one word, and how loudly it's yelled is your clue.
As for invectives:
(shills) means "feces". That's an unvoiced "s" it ends in, by the way. It's used to denegrate something, as you'd expect.
(murng-jooh) means "discomfort". It's used similar to "damn it" in English, to express unhappiness.
(n'zaych-sur) means "loser". Sometimes it's just abbreviated (n'zaych), which means "the losing". Similar to "dumbass" and other condescending insults in English.
(zhairk) means "meannie" or "jerk". This is used similar to "asshole" and other personal invectives in English. (zhairk-tsee) would be a more extreme form.
Hope these are enough to get you started, Michelle. The dictionary has many others...usually single nouns express the underlying idea when uttered.