Student or Learner
"Core modal verbs have only one form. They have no to-infinitive form, -ingform, past form or -ed form. We have to reword what we want to say by using other expressions:"
I got this explanation about semi modals from Cambridge Dictionary. Please explain to me the use of " what " in the sentence.
It replaces "the thing". In this case, it would be a sentence or a phrase.
We have to reword the sentence/phrase we want to say by using other expressions.
We use "what" in this way a lot, so you might want to look out for examples when you're reading English. Of course, it doesn't always mean "the word/phrase".
Do you know what you want for dinner?
You need to decide what you want for breakfast.
Please tell me what you are trying to say.
You must change into what you're wearing for the party.
You should stop what you're doing.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.