how come

How come you don't play now?

"How come" is another way to say "why" when asking a question.  Notice the following:

1. How come you never call me anymore?
   
2. How come she doesn't believe me?
   

retired

I've retired from soccer.

We usually use the word "retire" to talk about when we stop working because we are too old or have enough money and never have to work again.  Notice the following:

1. When are you going to retire?
   
2. He retired two years ago and has been traveling a lot since then.
   

these days

These days? No! I've no time.

"Recently" is another way to say "these days."  It is similar to "in the last few weeks."  Notice the following:

1. What do you do for fun these days?
   
2. He has been really busy with his studies these days.
   

hard

That's hard to say.

In this sentence "hard" can be replaced with "difficult."  The example sentence refers to something that is difficult to predict or expect.  Notice the following:

1. It's hard to believe you will be 23 years old tomorrow.
   
2. It was very hard for him to find a good job.
   

right now

Right now, there's a kid named Ronaldino.

"Currently" is another way to say "right now."  We can use this to talk about something in the immediate present.  Notice the following:

1. Where are you right now?
   
2. I need you to come home right now.  There has been an accident.