I learnt that some words such as important requires the subjunctive. Therefore,
"He studies every day."
becomes "he study every day" after "important", which results in
"It is important that he study every day."
However, DeepL Write suggests "It is important that he studies every day." rather than "It is important that he study every day."
Is the grammar I learnt at school is outdated? Or is DeelL Write wrong?
However, DeepL Write suggests "It is important that he studies every day." rather than "It is important that he study every day."
In careful speech, those two forms mean different things.
"It is important that he studies every day."
This statement means that he studies every day, and that fact is important.
You could restate it like this:
"The fact that he studies every day is important."
"It is important that he study every day."
This statement doesn't say whether he studies every day, but it says that he should study every day, and that is important.
It is this use that can be called subjunctive.
You can use the below sentence. "It's necessary for him to study every day"
Please note, It's better to use "necessary" instead of "important".
You may use the subjunctive "It is important that he study...". But it isn't required. The indicative form "It is important that he studies..." is also used and is correct.
English doesn't have a proper subjunctive. English tends to use other forms such as an embedded infinitive clause: "It is important for him to study". Or modal verbs "He should study; it's important!" Learners should try to avoid using the subjunctive forms and learn these alternatives.
