Choosing the Best Modal Verb to Complete a Sentence

“Should” is used to talk about obligation and give suggestions.  

 

They should take more vacation time.     (Giving a suggestion)

 

You should do your homework every night. (Explaining an obligation)

 

“Would” is used to discuss habitual action in the past.

 

As kids, we would play outside all summer.

 

However, “should/would” do have a little overlap. It roughly corresponds to the past tense of “shall/will,” as discussed above.

 

For most subject pronouns, “should” shows a stronger idea of command, promise, or assertion. For I and we, the opposite is true – “would” is stronger.  

 

I should think they are telling the truth.

is less certain than

I would think they are telling the truth.

 

If they did their homework, they would do better.

is not as strong as

If they did their homework, they should do better.