therefore   
amin' izany
therefore [Hallanger 1973]
amin' izao
therefore, now [Hallanger 1973]
amy
fa
for, therefore, because, that. Tandremo, fa masiaka ny omby: take care, for the ox is fierce. Be, fa mangidy: much but bitter. Milaza fa handeha izy: he says that he will go. [Richardson 1885]
for, therefore, because [Hallanger 1973]
ka
that, so that, and so; but, therefore. It is often followed by "dia". In the provinces, it is often "ko": Nantsoiny ka tonga aho (Called by him, and so I am come) ~ Nanantena anao ho tonga aho, ka tsy tonga hianao (I hoped you woud come, but you did not come ~ Nokapohinao ka kaody izy (Flogged by you, and therefore he is shy) [Richardson 1885]