·we use will to make predictions about the future.
humans won't live on mars
·we use will to talk about decision made at the time of speaking
I think i'll go home
·we use will to make promises and to offer help
You look tired. i'll cook diner
·we use going to to talk about a plan or intention in the future
i'm going to teach you about your home
·we can use going to to make a prediction based on present evidence
i can see now that our planet is going to explode
·we use the present continius to talk about an arrangement at a definite time in the future
are you going to cinema at 8 p.m.?
·zero conditional( to talk abouth general truths) : If+present simple-present simple
present simple-if+present simple
IF there isn't a signal, mobiles phones don't work
·first conditional(to talk about a future event which is probable): if+present simple-will+infinitive
If you drop you mobile in the water, it won't work
·second conditional(to talk about a situation which is imaginary, because it is impossible or improbable): if+past simple-would+infinitive
If a stranger needed to make a call, would you let them use your phone?
·third conditional(to talk about hypothetical situations in the past) : IF+past perfect-would have+past participle
If we had had enough money, we would have bought tickets to the football match
·used to (to talk about actions or situations that happened frequently in the past but don't happen now)
i used to have long hair and play the guitar