_O mánnkinn swá þatt ítt mannkínn._ Orm. 277.
With regard to the rhythmical treatment of trisyllables two classes of such words are to be distinguished, namely, (1) those in which the syllable bearing the primary accent is followed or (rarely) preceded by a syllable bearing a secondary accent, as e.g. _gódspèlles_, _énglìshe_, and (2) those in which the syllable bearing the primary accent is preceded or followed by a syllable wholly unaccented, as e.g. _bigínnen_, _òvercóme_, _crístendòm_, _wéathercòck_. In the latter case level stress is hardly ever met with, as the natural word-accent would be interfered with to an intolerable extent by accentuations like _cristéndom_, _weathércock_, _ovércome_, _bíginnén_, _fórgottén_, _béhavióur_, &c.
Words like these therefore can in regular iambic or trochaic verse be used only with their natural accentuation, and hence those syllables which either have the primary or the secondary accent are always placed in the arsis, and the unaccented ones in the thesis, e.g.: _To wínnenn únnder Crísstenndóm_ Orm. Ded. 137; _off þátt itt wáss bigúnnenn_ ib. 88; _Though the séas thréaten, théy are mércifúl_ Shakesp. Temp. V. 178; _Ónly compóund me wíth forgótten dúst_ id. 2 Hen. IV, IV. v. 116, &c. On the other hand, when primary and secondary accent occur in two adjacent syllables level stress is very common, in Middle English, especially between the first and the second syllable, as _g+o+dspélles háll[gh]he láre_ Orm. 14, more rarely between the second and the third syllable, as _þa Góddsp+e+ll+é+ss neh álle_ ib. 30; it also occurs in Chaucer's poems, as _For thóus+a+nd+é+s his hóndes máden dýe_ Troil. v. 1816; in the same way Modern English words are treated to fit the rhythm, as e.g. _mídsùmmer_, _faíntheàrted_, in _Farewéll_, _f+á+int-h+éa+rted ánd degénerate kíng_ Shak. 3 Hen. VI. I. i. 138; _And górgeous ás the sún at míds+u+mm+é+r_ 1 Hen. IV, IV. i. 102. With the more recent poets this latter kind of rhythmical accentuation becomes the more usual of the two, although the nature and the meaning of the compound word always play an important part in such cases.
With regard to their accentuation and metrical employment words of four syllables also fall into three classes: 1. Inflected forms of words belonging to the first group of trisyllables, like _crístendómes_, which can be used in the rhythm of the verse only with their natural accentuation; 2. words like _fordémde_ (first and last syllable unaccented, the second syllable having the chief accent) with a determinative prefix, as e.g. _únfordémde_; these likewise are used in the rhythm of the verse according to their natural accentuation; 3. words of the third group with a prefix which either has the secondary accent, or is unaccented, as _ùnwíslìce_ or _iwítnèsse_; the metrical usage of these is regulated according to the rules for the trisyllabic words. The same is to be observed with regard to words of five and six syllables like _únderstándìnge_, _únimételiche_, which, however, are only of rare occurrence.