Hi Caxio. Did you know that in South Africa English is one of our offical languages? There are many native English speakers here. Just like Australia, we are post British colonial country. To answer your questions: Traditionally, British grammar taught that shall was used with I/we and will with you/he/she/they for the future. Today, will is used for all people and is the normal choice. Shall sounds formal, old-fashioned, or is used in specific phrases. 1a vs 1b: I shall write tomorrow vs I will write tomorrow Both are correct and mean the same thing. I will write tomorrow is natural, modern English. I shall write tomorrow is very formal, old-fashioned, or literary. 2a vs 2b: Who will lend me a cigarette? vs Who shall lend me a cigarette? Who will lend me a cigarette? is correct and natural. Who shall lend me a cigarette? is grammatically possible, but sounds very old-fashioned and unnatural. Today, shall is mainly used in questions like: Shall we go? Shall I help you? 3a–3d: go you shall / go you should / you should go / go you will These use unusual word order for emphasis. You should go is normal way to give advice. Go you shall is dramatic or formal. It sounds like a command or a strong promise (“You will go.”) Go you should is old-fashioned way of giving advice. Go you will sounds like a prediction or a prophecy. So in modern English, use: will for the future should for advice shall mainly for offers, suggestions, or very formal writing. Hope that helps