Put yourself in another person's shoes by using the modal "would"
The word "would" is one of the most complicated words in English, as it has many uses and meanings. However, the most common use of "would" is to express an intention or certain result in a situation that is unlikely, impossible, or hypothetical.
For example, when you imagine being a child again, you can describe your intention in this situation by using "would":
I would play outside all day (if I were a child again)
You can also use "would" this way when you are imagining yourself in another person's situation, because you are not really in the situation that the other person is experiencing. For example, if your friend tells you that he lost his job, you are not the person who lost their job, so you need to use "imaginary" language to describe your future intention in that situation:
I would look for another job (if I were in your situation / if I lost my job)
When people tell you their situation and you want to respond with advice, you can use "would" to express this advice, which tells them that you are imagining yourself in their situation and what you "would" do in that situation: "I would take the subway", "I would wait", "I wouldn't (buy them)."
In each example below, the person responds and offers their advice by using "would". This really means "if I were you, I would..." or "if I were in your situation, I would...":
What's the best way to get there? = "I'd take the subway."
Should I go to the store now or later? = "I'd go later. It's probably busy right now."
The shoes are $200. Should I buy them? = "I wouldn't. I'd wait for them to go on sale."
Three things to note from the examples above:
You don't have to repeat the verb if it's obvious. In the third example above, the person can give advice just by saying "I wouldn't", which means "I wouldn't buy them" but saying "buy" (and "them") is unnecessary because it's obvious.
Don't use "will" - the word "will" describes the real future in your real life. If you are imagining another person's life you have to say "I would", not "I will".
You can use the short form "I'd" instead of "I would" but make sure the person can hear your pronunciation of the "d" sound or it will sound like present simple ("I'd go" vs. "I go")
Use "I would" to respond to the comments below:
I want to travel. Which country do you recommend?
I'm not sure whether I should get a cat or a dog. What do you think?
My boss always calls me at home. What should I do?
I want to lose weight quickly but I'm not sure how I can do it.
Do you think I should make a reservation at the restaurant?
Some possible responses are below:
I'd go to Japan. It's safe and there are many interesting places to see.
I'd get a cat. They are much easier to take care of.
I'd stop answering your phone, and if he keeps calling you, I'd talk to him about it.
I'd only eat two meals a day instead of three, and I'd start exercising every day.
I would. It can guarantee a table for us later. (note: this does not mean that I will make the reservation. My friend is making the reservation - I am only giving advice to her)