Help needed for checking English

[Carolus Raeticus]

Salvete!

I have finished transcribing Carl Meissner's Lateinische Phraseologie in the English version by H.W. Auden (Archive.org's 1894-edition) and will soon upload it. However, I need your help with the preface. For that I am translating (more or less freely) sections from the original German preface by Carl Meissner. Could you please tell me whether the following is proper English and mark any errors? It does not have to be Shakespeare, but it should not be studded with erros.
Here are the two sections I want to use:

It cannot be denied that, while grammatical competence is rightly aimed at in the classical secondary schools [the German „Gymnasien“], and probably successfully so, the ability to freely use the language has not always kept abreast of it. The explanation for this can be found in one-sided concentration on purely formal aspects easily leading to neglect of the language itself as expressed in its expressions and phrases.It is, however, not enough to merely educate the pupils concerning grammar and style. Instead, one also has to methodically aim at enabling the pupil to have at least a certain command of the language material. This goal, however, will not be attained either by time-consuming dictation of the phrases, or by leaving it up to the pupil to collect them. Instead the pupil has to be offered a definite but narrow stock of phrases for firm and sure acquisition which will then be available to him in the composition exercises.
Accordingly, only the most common and frequent phrases have been included in this phraseology, whereas all phrases have been omitted for which the pupil probably will have no use. It is then up to the pupil to broaden the material offered in this phraseology based on his reading matter.

The phrases themselves are arranged in 17 rather comprehensive categories, and these in turn have been divided into smaller groups for easier overall view. In doing so I have followed practical rather than strictly logical considerations. Furthermore, I found it appropriate to proceed from the Latin phrases in order not to stray too often into comparative stylistics which would have been unavoidable due to the differences of Latin and German idioms. I solely endeavoured to show which words can be combined in Latin, not how this or that German idiom might be best expressed in Latin.

I would appreciate your help,

Carolus Raeticus

[daivid]

I don't often visit this section of the forum so I hope a few comments are still of use

It cannot be denied that, while grammatical competence is rightly aimed at in the classical secondary schools [the German „Gymnasien“], and probably successfully so, the ability to freely use the language has not always kept abreast of it. The explanation for this can be found in one-sided concentration on purely formal aspects easily leading to neglect of the language itself as expressed in its expressions and phrases.It is, however, not enough to merely educate the pupils concerning grammar and style. Instead, one also has to methodically aim at enabling the pupil to have at least a certain command of the language material. This goal, however, will not be attained either by time-consuming dictation of the phrases, or by leaving it up to the pupil to collect them. Instead the pupil has to be offered a definite but narrow stock of phrases for firm and sure acquisition which will then be available to him in the composition exercises.
Accordingly, only the most common and frequent phrases have been included in this phraseology, whereas all phrases have been omitted for which the pupil probably will have no use. It is then up to the pupil to broaden the material offered in this phraseology based on his reading matter.

"the ability to freely use the language has not always kept abreast of it."
better as
"the ability to freely use the language has not always kept up."

"whereas all phrases have been omitted for which the pupil probably will have no use."
better as
"whereas all phrases for which the pupil probably will have no use have been omitted.

The phrases themselves are arranged in 17 rather comprehensive categories, and these in turn have been divided into smaller groups for easier overall view. In doing so I have followed practical rather than strictly logical considerations. Furthermore, I found it appropriate to proceed from the Latin phrases in order not to stray too often into comparative stylistics which would have been unavoidable due to the differences of Latin and German idioms. I solely endeavoured to show which words can be combined in Latin, not how this or that German idiom might be best expressed in Latin.

"phrases themselves are arranged in 17 rather comprehensive"
"fairly" would be better than "rather"

"for easier overall view. "
better as
" for an easier overall view. "

" I solely endeavoured to show"
better as
" I endeavoured solely to show"

I don't think any of those are truly errors but I think my alternatives flow a little better