These words usually come at the beginning of a sentence and describe the manner of the activity.

'eQ just now, a moment ago
DaH now
Do' luckily
Do'Ha' unfortunately
Hochlogh all times, always (emphatic)
QIt slowly
SIbI' immediately
SIbI'Ha' later, eventually
SetqIn alternatively, instead, rather
batlh honored, with honor
batlhHa' dishonorably
bong accidentally, by accident
chIch purposely, on purpose, intentionally
chaq perhaps
ghIq then, subsequently
ghaytan likely
ghaytanHa' unlikely
jaS differently
jaSHa' similarly
jay' intensely (invective)
loQ slightly, little bit
meQHam ironically, counterintuitively, incongruously
motlh usually, typically, as expected, expectedly
nIteb alone, acting alone
nItebHa' together
neH only, just
ngugh then, at that time
nom fast, quickly
not never
pIj often, frequently
pIjHa' seldom, infrequently
paghlogh zero times, never (emphatic)
pay' suddenly
pe'vIl forcefully, by force
qen recently, a short time ago
reH always
roD usually, customarily, habitually, regularly
rut sometimes, occasionally
tagha' finally, at last
tlhoS almost, nearly, virtually, not quite, barely
tlhoy overly, to an excessive degree, excessively, too much
tugh soon
vabDot moreover, in addition, even, including, also
vaj so, then, thus, in that case
wa'logh once
wej not yet
wejHa' already

Examples:

bong yaS vIHoHpu' I accidentally killed the officer. (yaS officer, vIHoHpu' I killed him/her)

batlh Daqawlu'taH You will be remembered with honor. (Daqawlu'taH somebody continues to remember you)

vaj Daleghpu' Then you have seen it. (Daleghpu' you have seen it)

wej vIlegh I don't see him/her yet (vIlegh I see him/her)

One word fits somewhat awkwardly into this category:

neH only, merely, just

Unlike the other adverbials, it follows the verb which it modifies. The semantic effect is one of trivializing the action.

qama' vIqIppu' neH I merely hit the prisoner. (qama' prisoner, vIqIppu' I hit him/ her)

Duj yIQotlh neH Just disable the ship! (Duj ship, vessel, yIQotlh disable it!)

The use of neH in the preceding sentence implies that the ship is to be disabled, but not damaged further.

Also unlike the other adverbials, neH can follow a noun. In such cases, it means only, alone.

yaS neH only the officer, the officer alone

jonta' neH only the engine

There is also a negative form of this adverb that can also be used after a noun to mean not only.

chaH neHHa' wovmoH jul the sun lit up not only them

tlhIngan Hol neHHa' vIjatlh I speak not only Klingon

Adverbials sometimes occur alone, functioning more or less as exclamations (section 5.5). For example:

nom Move fast! Move quickly!

wej Don't do it yet!

tugh Hurry up!

The earlier belief that adverbials come only at the beginning of sentences turns out to be not quite accurate. For a more correct description, see Section 6.7.

There is a second word (in addition to neH only, merely) which fits into this category despite its very peculiar behavior:

jay' intensely

This word not only intensifies whatever is being said, it turns the whole phrase into an invective. Alone among the adverbials, jay' always comes at the end of the sentence.

qaStaH nuq jay' What the #$*@ is happening? (qaStaH it is occurring, nuq what?)

mIch 'elpu' jay' They've entered the #$%@ sector! (mIch sector, 'elpu' they've entered it)

Negative Adverbials?
Source: <{HolQeD} 4:4>, page 11

The following snippet from HolQeD is postulation by the author of the article. Another analysis of the situation is that all adverbs are fossilized constructions that just appear to be a word plus a suffix. 

The word for dishonorably is batlhHa'. This is clearly the adverbial batlh in an honored fashion plus a suffix -Ha', which might be analyzed as the negative suffix that follows verbs or else as a suffix identical in form (and meaning?) to it, but which appears with adverbials.

Whether this -Ha' can be added to all adverbials is not clear. The notes taken while working with Maltz indicate that he balked at vajHa' not thus but accepted Do'Ha' unfortunately. Information on other adverbials has not yet been uncovered, though it is probably in the notes somewhere.