=T=, meeting with the vowel =i=, under certain circumstances becomes =s=.
=37.= =T= in the last syllable of a word, when preceded by a vowel or by
=l=, =n=, =r=, becomes =s= when a final =e= is rejected or changed into
=i=. E.g. in the nominative of the root =vete=, _water_, the final =e=
becomes =i= by rule, and =t= changes to =s=, forming =vesi=. Similarly
when the final =e= of =hyvyyte=, _goodness_, is rejected =t= becomes =s=,
forming the nominative =hyvyys=; so also =jälte= becomes =jälsi=, and
=varte=, =varsi=.
=38.= =T= also becomes =s= before =i= in the plural of ordinal numbers
whose stem ends in =-nte=. E.g. the essive singular of stem =neljänte=,
_fourth_, is =neljäntenä=; in the plural the corresponding case is
=neljänsinä=, for =neljäntinä=.
=39.= The plural of stems ending in =-ute=, =-yte=, forms the essive
and other analogous cases from a stem ending in =-ksi=. =Suuruus=,
_greatness_, has for the sing. the stem =suuruute= (e.g. essive
=suuruutena=), but forms in the plur. =suuruuksina=, etc. So also
from =hyvyyte=, _goodness_, comes from the sing. =hyvyytenä=, and
the plur. =hyvyyksinä=.
=40.= =T= in the last syllable of a verb, preceded by a double vowel or
=l=, =n=, =r=, changes to =s= before the =i= of the imperf., the vowels
=a=, =ä= being suppressed. Thus from =pyytää=, _to ask_, comes =pyysi=
(for =pyytäi=); from =taitaa=, _can_, =taisi=. But =pitää=, _to hold_,
makes =piti=, because this vowel is simple.
=Nousee=, _he arises_, forms the imperfect =nousi=, but =noutaa=, _he
brings_, makes =nouti=, to distinguish it from the other. Similarly
=kyntää=, _to plough_, generally forms its imperfect =kynti=, to
distinguish it from the same tense of =kynsiä=, _to scratch_.
In poetry forms like =kielti=, for =kielsi=, are found, and in the
ordinary language a number of verbs which should by the above rule form
the imperfect in =si=, either keep =ti=, as =hoiti= (=hoitaa=, _to
look after_), =jouti= (=joutaa=, _to have time_), or have alternative
forms, =hääti= or =hääsi= (=häätää=, _to keep off_), =sääti= or =sääsi=
(=säätää=, _to place_), =kiiti= or =kiisi= (from =kiitää=, _to hasten_),
=hyyti= or =hyysi= (=hyytää=, _to freeze_), =syyti= or =syysi= (=syytää=,
_throw out_), =sieti= or =siesi= (=sietää=, _to bear_), =jäyti= or
=jäysi= (=jäytää=, _to gnaw_).
=T= always becomes =s= in the imperfect of contracted verbs, =lupata=,
_to promise_, pres. =lupaan=, impf. =lupasin=.
The combination =ts= is pronounced in dialects as =tt= or =ht=; e.g.
=metsä=, _a forest_, appears as =mettä= or =mehtä=.
=41.= =K= before =t=, =d=, =n= becomes =h=. E.g. from the root =teke=,
whose final vowel is liable to be rejected, come =tehtiin=, =tehdään=,
=tehnen=, and also =tehkää=.
=42.= But =h= before =s= becomes =k=. Thus the stems =yhte=, _one_,
=kahte=, _two_, =haahte=, _a ship_, form the nominatives =yksi=, =kaksi=,
=haaksi=, =te= becoming =si= by the rules previously given, and =h=
changing to =k=.
=43.= In contracted words (_v._ page 18) =h=, when left as a final letter,
becomes =s=, =t=, or the aspiration. Stem =vieraha=, nominative =vieras=,
for =vierah=; stem =kevähä=, nominative =kevät=, for =kevähä=; stem
=venehe=, nominative =veneʻ=, for =venehe=.
Though the above rules are given as being convenient for grammatical
purposes, there is no doubt that in all these cases =h= is a weakening of
some other letter; indeed, there is reason to think it is never original
in Finnish. =Vieras= represents an original =vierasa=, and the genitive
=vierasan= is weakened into =vierahan= and =vieraan=. Similarly in
=yksi=, =yhden=, the =k= is more primitive.
=44.= =N=, after =l=, =n=, =s=, is frequently, though not always,
assimilated, especially in verbs. Thus =tul-nut=, =pur-nut=, =pes-nyt=,
become =tullut=, =purrut=, =pessyt=.
=45.= In polysyllabic verbs =n= becomes =t= before =k= and =t=. Thus root
=pakene= makes in the imperative =paetkaa= (for =pakenkaa=, which becomes
first =paketkaa=) and infinitive =paeta=. (The steps are =pakenetaʻ=,
=pakentaʻ=, =pakettaʻ=, =paettaʻ=, =paeta=.)
=46.= =M=, at the end of a word, always becomes =n=. Stem =avaime=,
_a key_, nominative =avain=, for =avaim=. Similar is the formation of the
nominatives of superlatives: =kovimpi= becomes =kovimp= by rejection of
the final vowel, and then =kovim= (rule =24=), which changes to =kovin=.
=47.= =M= also becomes =n= before terminations beginning with =t= or =n=.
Thus the stem =rahattoma=, _moneyless_, shortened to =rahatom=, makes
=rahatonta= and =rahatonna= in the partitive and essive cases.