G. We use 'will' to talk about the future and to say what we believe will happen, and to talk about what people want to do or are willing to do to make promises and offers.
a. 'would' is the past tense form of 'will' to talk about the past and to talk about hypotheses (things that are imagined rather than true), and for politeness.
G1. 'Will' to say what we believe will happen in the future. (e.g. We'll be late. We will have to take the train.)
a. We use 'would' as the past tense of 'will' to say what we believed would happen. (e.g. I thought I would be late ~ so I would have to take the train.)
G2. We use 'I will' or 'We will' to make offers and promises. (e.g. I’ll give you a lift home after the party. We will come and see you next week.)
Idiom 365
Knee Jerk Reaction: a quick and automatic reaction without considering carefully
Example: Their response was 'NO' without considering, even thinking; it was a knee-jerk reaction.