For the imperative the simple verb is used: o lea amu go away; fasi may be added for politeness: lea fasi amu you go!
3. Negative Particles: The foregoing particles are not used in negative sentences. The negative particles are langi, e langi, si. These may be combined: nia langi si saea he does not know it, e langi mu si rongoa ma e langi mu si saea you have neither heard it nor seen it, e langi nau gu si lea I am not going, e langi uri ta ai e adasia no one has seen it, e langi asia not at all. The verbal particle ka may be used in negative sentences with the addition of si, kasi bobola it is not fitting. The dehortative and the negative imperative is fasia: fasia oko lea do not go! fasia gera ka adasia let them not see it, o fasia oko luia do not forbid it.
Genitives: ni, i are used to express purpose.
4. Suffixes to verbs: There are certain terminations which, when added to neuter verbs or to verbs active only in a general way, make them definitely transitive or determine their action upon some object. These are of two forms:
a. A consonant with i: fi, li, mi, ni, ngi, si, or i by itself; e.g. tau, taufi; mae, maeli: ano, anomi; mou, mouni; sau, saungi; ada, adasi; manatat, manatai; to the verb taa to be bad, both si and li are added and the causative fa is prefixed: fataasi, fataali, to make worse. Certain verbs which are active in Lau are neuter in Sa'a: angai to lift, angaia lift it, Sa'a angainia; faodo to straighten, faodoa straighten it, Sa'a ha'aodohie; famae to kill, famaea, Sa'a ha'amaesie; famou to frighten, famoua, Sa'a ha'ama'usie.
b. The termination ai is suffixed by itself to nouns to convert them into verbs, sato, satoai. When this syllable ai is suffixed to verbs the genitive ni may be added, and to the form aini the consonants f, m, ng, t, are prefixed: oli to return, olifaini to carry back, ala to answer, alamaini to consent, sau to become, saungaini to make, tagala lost, tagalangaini to drive out, foaa to pray, foaataini to pray for. The forms in ai are also used intransitively: tege to fall, tegelai lost, oli to turn, olitai converted.
The genitive ni (cf. M. L., p. 532) is often omitted and is not invariably used as it is in Sa'a, since the form ai without the addition of ni is transitive: gonitai to receive, gwoutai or gwoutaini to be left alone, oalangai to apportion, fatolamai to command.
Ani appears to be used by itself as a transitive suffix: ui to throw, uiani to throw away, laga to drive, lagaani to drive away, taba to strike, tabaani to destroy; ani is used also with too to hit, tooani to understand.
With either class of suffixes there is no difference in meaning between one suffix and another.
5. Prefixes to verbs: These are causative and reciprocal.