Many striking differences between classical and medieval Latin are found in orthography.
Perhaps the most striking difference is that medieval manuscripts used a wide range of abbreviations by means of superscripts, special characters etc.:
for instance the letters "n" and "s" were often omitted and replaced by a diacritical mark above the preceding or following letter.
Apart from this, some of the most frequently occurring differences are as follows.
Clearly many of these would have been influenced by the spelling, and indeed pronunciation, of the vernacular language, and thus varied between different European countries.

Following the Carolingian reforms of the 9th century, Carolingian minuscule was widely adopted, leading to a clear differentiation between capital and lowercase letters.

A partial or full differentiation between v and u, and between j and i.
The diphthong ae is usually collapsed and simply written as e (or e caudata, ę); for example, puellae might be written puelle (or puellę).
The same happens with the diphthong oe, for example in pena, Edipus, from poena, Oedipus.
This feature is already found on coin inscriptions of the 4th century (e.g. reipublice for reipublicae).
Conversely, an original e in Classical Latin was often represented by ae or oe (e.g. aecclesia and coena), also reflected in English spellings such as foetus.

Because of a severe decline in the knowledge of Greek, in loanwords and foreign names from or transmitted through Greek, y and i might be used more or less interchangeably: Ysidorus, Egiptus, from Isidorus, Aegyptus.
This is also found in pure Latin words: ocius ("more swiftly") appears as ocyus and silva as sylva, this last being a form which survived into the 18th century and so became embedded in modern botanical Latin (also cf.
Pennsylvania).

h might be lost, so that habere becomes abere, or mihi becomes mi (the latter also occurred in Classical Latin); or mihi may be written michi, indicating that the h had come to be pronounced as k or perhaps kh.
This pronunciation is not found in Classical Latin.

The loss of h in pronunciation also led to the addition of h in writing where it did not previously belong, especially in the vicinity of r, such as chorona for corona, a tendency also sometimes seen in Classical Latin.

-ti- before a vowel is often written as -ci- [tsi], so that divitiae becomes diviciae (or divicie), tertius becomes tercius, vitium vicium.

The combination mn might have another plosive inserted, so that alumnus becomes alumpnus, somnus sompnus.

Single consonants were often doubled, or vice versa, so that tranquillitas becomes tranquilitas and Africa becomes Affrica.

Syncopation became more frequent:  vi, especially in verbs in the perfect tense, might be lost, so that novisse becomes nosse (this occurred in Classical Latin as well but was much more frequent in medieval Latin).

These orthographical differences were often due to changes in pronunciation or, as in the previous example, morphology, which authors reflected in their writing.
By the 16th century, Erasmus complained that speakers from different countries were unable to understand each other's form of Latin.

The gradual changes in Latin did not escape the notice of contemporaries.
Petrarch, writing in the 14th century, complained about this linguistic "decline", which helped fuel his general dissatisfaction with his own era.
Many striking differences between classical and medieval Latin are found in orthography. Perhaps the most striking difference is that medieval manuscripts used a wide range of abbreviations by means of superscripts, special characters etc.: for instance the letters "n" and "s" were often omitted and replaced by a diacritical mark above the preceding or following letter. Apart from this, some of the most frequently occurring differences are as follows. Clearly many of these would have been influenced by the spelling, and indeed pronunciation, of the vernacular language, and thus varied between different European countries.
Following the Carolingian reforms of the 9th century, Carolingian minuscule was widely adopted, leading to a clear differentiation between capital and lowercase letters.
A partial or full differentiation between v and u, and between j and i.
The diphthong ae is usually collapsed and simply written as e (or e caudata, ę); for example, puellae might be written puelle (or puellę). The same happens with the diphthong oe, for example in pena, Edipus, from poena, Oedipus. This feature is already found on coin inscriptions of the 4th century (e.g. reipublice for reipublicae). Conversely, an original e in Classical Latin was often represented by ae or oe (e.g. aecclesia and coena), also reflected in English spellings such as foetus.
Because of a severe decline in the knowledge of Greek, in loanwords and foreign names from or transmitted through Greek, y and i might be used more or less interchangeably: Ysidorus, Egiptus, from Isidorus, Aegyptus. This is also found in pure Latin words: ocius ("more swiftly") appears as ocyus and silva as sylva, this last being a form which survived into the 18th century and so became embedded in modern botanical Latin (also cf. Pennsylvania).
h might be lost, so that habere becomes abere, or mihi becomes mi (the latter also occurred in Classical Latin); or mihi may be written michi, indicating that the h had come to be pronounced as k or perhaps kh. This pronunciation is not found in Classical Latin.
The loss of h in pronunciation also led to the addition of h in writing where it did not previously belong, especially in the vicinity of r, such as chorona for corona, a tendency also sometimes seen in Classical Latin.
-ti- before a vowel is often written as -ci- [tsi], so that divitiae becomes diviciae (or divicie), tertius becomes tercius, vitium vicium.
The combination mn might have another plosive inserted, so that alumnus becomes alumpnus, somnus sompnus.
Single consonants were often doubled, or vice versa, so that tranquillitas becomes tranquilitas and Africa becomes Affrica.
Syncopation became more frequent:  vi, especially in verbs in the perfect tense, might be lost, so that novisse becomes nosse (this occurred in Classical Latin as well but was much more frequent in medieval Latin).
These orthographical differences were often due to changes in pronunciation or, as in the previous example, morphology, which authors reflected in their writing. By the 16th century, Erasmus complained that speakers from different countries were unable to understand each other's form of Latin.
The gradual changes in Latin did not escape the notice of contemporaries. Petrarch, writing in the 14th century, complained about this linguistic "decline", which helped fuel his general dissatisfaction with his own era.
Medieval Latin