Latvian words are stressed on the first syllable. Exceptions to this rule (e. g.,
neviens, pusotra) are rare, and are indicated in notes to the vocabularies.
Long vowels and diphthongs (and for this purpose sequences of vowel plus
r, l, ļ, m, n, ņ are considered diphthongal) are subject to certain intonation
patterns. In a few areas three patterns are distinguished: the even intonation
(stieptā  intonācija), the falling intonation (krītošā  intonācija) and the broken
intonation (lauztā  intonācija).

The even tone calls for very little comment: the vowel or diphthong is
uttered on a level tone with no significant variation in intensity. The falling
tone3 begins more loudly, falling off towards the end.
The broken tone4 divides the duration of the vowel or diphthong into two
sections : a rising, tense and loud beginning is followed in mid-syllable by a
noticeable weakening, and a relaxed or weakened, sometimes even whispered,
final segment.

However, many areas have only a two-way contrast; in some the falling and
broken intonations are fused, in others the falling and even. These intonational variations limit the generalization that can be made to the broad statement that for most speakers the basic distinction is between an even intonation and a non-even intonation.5

In view of these variations, and the fact that the intonation patterns of the literary language have not been fully investigated,6 it would be illusory to attempt a rigid doctrine, just as it would be impossible to allow for even the major variations; we have therefore decided to limit our commentary to those cases where total homophony is prevented only by an intonation distinction, i.e., where the syllable intonation performs a distinctive function.

T.G. Fennell H. Gelsen, A Grammar of Modern Latvian,

1 See Mūsdienu Latviešu literārās valodas gramatika, I, p. 37.
2 The classification and description of Latvian phonemes are treated in more detail in op. cit., pp. 20-37. See also Laua, A., Latviešu Iiterārās valodas fonētika.
3 See Endzelins, Latviešu valodas gramatika, p. 35.
4 See op. cit., p. 34.
5 See Mūsdienu latviešu literārās valodas gramatika, I, p. 68.
6 Ibid.