There is one very simple solution to your problem. You have to refer to facts not to your own opinion. Such facts could be, for instance, a passage from a respected book in the field. Or an automatic grammar/spell checker such as Grammarly.

You can say, I was not sure about my writing, therefore I checked the text with Grammarly. Here are the mistakes.

In order to effectively argue against this defense, one has to be very knowledgeable in grammar and stylistic of English language. This program is very strong.

There is one very simple solution to your problem. You have to refer to facts not to your own opinion. Such facts could be, for instance, a passage from a respected book in the field. Or an automatic grammar/spell checker such as Grammarly.

You can say, I was not sure about my writing, therefore I checked the text with Grammarly. Here are the mistakes.

In order to effectively argue against this defense, one has to be very knowledgeable about English grammar and style. This program is very strong.