In our separate sections on each tense, you will see that adding information about time changes the intended meaning of your sentence. If the information is left out, this often indicates that the participants in a conversation understand what is left unsaid because of the circumstances in which you are speaking. There are lots of other details which might be unsaid or implied, but we will focus on time, because time is what helps us decide which tenses to use.
Imagine you had a crazy party in your house, and when you wake up in the morning, a good friend offers to help you tidy up. They might say, "I’ll help you tidy up", using the Future Simple to express their intent to do something right now, in the Present. In our Tenses Overview, we mentioned how the Future Simple tense can be used to talk about things that you intend to do right now, or maybe have even started doing. Native English speakers use this tense very often to speak about things they are just about to do. Let me give you another example:
You have just stepped up to the counter in your favourite store, and the Sales Assistant asks if you would like to pay by cash or card. You’ll also hear this asked very regularly in a Supermarket, maybe when you’re buying all that food and drink for your crazy house party. You could either be looking in your wallet or handing your card over when you say, "I’ll pay by card". The action of paying hasn’t begun yet, but you express your immediate intent to pay by card, using the Future Simple:
You might think that to say, "I’ll be paying by card", is exactly the same, but it’s not. Instead, this use of the Future Continuous would sound like you intended to pay sometime later. It might be something you’d like to make clear at the start of the meal.
Now, this pattern is easy to remember when the context – the situation – is already clear. You are being asked how you would like to pay, and so you answer the question with a simple, short sentence. The same applies to your messy house after the party. The context of the mess means that when your friend says, "I’ll help you tidy up", they mean that they’ll help right now: