Is it better to study grammar or practice speaking?

Both, but not at the same time. Grammar study gives you forms to use; speaking practice makes them available under pressure. If you can only do one each day, spend it speaking and correct the recurring mistakes afterward, because grammar you never say out loud stays in the part of your memory that only works when you have time to think.

If you have twenty minutes, spend fifteen speaking and five reviewing the mistakes you actually made. A grammar rule you have said out loud five times, in your own sentences, becomes available while you are thinking about something else; the same rule read in a book tends to stay available only when you have time to consult it. Let your own errors decide which grammar you study next.

How to Speak English Fluently and Confidently: A Practice Routine →