What is the added value of the dt rule and language rules that change?

Answer

There are several aspects to your question. The important thing is to realize the following principles.

(a) language is primarily a spoken medium and written language is a derivative of this, a code that should approach the spoken language in some way. Remember that we learn to speak before we learn to write and that there are languages ​​that do not have written code.

(b) language is constantly evolving from generation to generation. In some cases we are aware of this (eg the vocabulary specific to young people differs from that of older generations). In other cases, a language evolves spontaneously, without us realizing it (eg in pronunciation).

(c) a language is not completely homogeneous. There are geographical differences (think of the pronunciation in the North and in the South of our language area, in West and East), but also social, occupational and generational differences.

The spelling (the written code) is determined according to fixed rules and is standardized. This means that it cannot evolve in the same way, nor can it reflect all variations within the language (which would require different spellings). Written language is thus inevitably “more conservative” and is adapted from time to time. The double written o you mention has to do with an old difference in pronunciation between an open and a closed vowel, a difference that you can still find in certain dialects. One statement was written double, the other single (eg cabbages and coals).

The fact that languages ​​have internal variation in pronunciation also does not make it possible to come up with a spelling that exclusively reflects the pronunciation. There are languages ​​that have developed a spelling that takes into account as much as possible the phonetics (pronunciation) of that variant that is accepted as the norm, but one can also take into account other components in the language, e.g. the morphology (the forms of a language ). The latter is what happens with the dt rules. Here the speller did not rely on phonetics, because then you would always have to write a t at the end of a word, but on the form. It is a choice between two economic principles. Now take the word “word”. According to the phonetic rules I could choose word (singular) and words (plural). It is clear that I then have two spellings and in a sense lose the unity of the word “word” in the script. Following the morphological logic, I always write the word “word” in the same way, which is also the phonetic rule: word, words.

The “learning difficulty” of dt, which the speller built in, has to do with a typical phonetic feature of Dutch, where a voiced consonant (d, b, g, v) is dulled at the end of a word. To avoid having to replace the voiced consonant with a voiceless consonant at the end of a word, we keep writing the same consonant: web, web, but whack.

For verbs, the morphology is a little more complicated, because the third person ends in -t with just about all verbs: speaks, begins, jumps, etc. The speller has kept that morphological rule (the third person ends in -t) with verbs whose stem ends in -d. Hence our “difficult” dt rule with I become, he becomes.

So everything has to do with the choice between two language systems: the phonological (voiced consonants dull at the end of a word) or the morphological (the third person of the present tense ends in -t).

Summarized :

Written language is standardized vs. spoken language is variable.

Every language is constantly changing vs written language is more conservative.

The spelling rules take into account not only pronunciation, but also other linguistic aspects, such as morphology (grammar) or the origin of a word (electricity with k because it comes from Greek, product with c because it comes from Latin).