I think that

(a)   que

Where

(a)  

On one side...on the other side....

Por un ______... por ______lado

(a)  

For example

Por (a)  

Thanks to

(a)   a

Firstly

(a)  

Afterwards/ then

(a)  

Before

(a)  

Finally

(a)  

I hope I can go

Espero _______ __

(a)  

I hope I can do

________ poder _______

(a)  

I have always wanted to do

_________ he querido _______

(a)  

I have always wanted to go

Siempre he (a)   ir

I have always wanted to learn

________ he querido ____________

(a)  

I would have liked to go

Me (a)   gustado ir

I would have liked to do

Me hubiera _________ _________

(a)  

If the weather is good I will go to the park

___ hace buen tiempo ____ al parque

(a)  

If the weather is bad I will go to the cinema

Si hace ______tiempo ____ al cine

(a)  

If I had the money I would go

Si _________dinero ____

(a)  

If I had time I would do

Si _________ tiempo _______

(a)  

If I had money I would buy

Si ________ dinero _________

(a)  

It was

(a)  

It had

(a)  

there was

(a)