"I will go to the cinema tonight." Indicates you have very recently decided to go to the cinema tonight. "I'm going to the cinema tonight." This indicates that you already have a plan to go to the cinema. Regarding the other 4 sentences, number 1 and 2 are correct and indicate that in a few seconds you will call this person. Number 3 means you have already dialed the number and are waiting for them to pick up. Number 4 isn't correct. Hope that helps!

Hi Yuri! I'll call you now - this is a decision made at the time of speaking. the speaker has decided just that moment what he will do. I'm going to call you now - this is more of a planned action i'm calling you now - this is an action happening at the moment of speaking I call you now - this does not work grammatically. "Now" is not a time marker used with the present simple

The short answer is that "will" and "be going to" are exactly the same. The long answer is that they're exactly the same, but people prefer to use them in different situations (as Helen and Greg described). Don't caught up worrying about which is right and which is wrong, because they express the same thing. Native speakers DO use them differently, but the difference is that they are more natural in different contexts rather than a difference in meaning.

Use "I'll call you now." We also use "will" to indicate a promise or intention by the speaker. "I'm going to call you now" makes me think you are in the process of picking up your phone to dial it. Alternately, you're trying to reassure me that you will call. Maybe my last message seemed a little annoyed? "I'm calling you now" means you have dialled the number and are waiting for me to pick up. "I call you now" is very clumsy English and a mistake made by elementary students. Native speakers will never use this. "I call you" means a general habit, but "now" is a specific time. They don't match.

Thank you rose! And thank you for everyone. It is very hard to pick just one person for the best answer! You all are good teachers!