English grammar is fairly simple to understand, once all the basic rules are cleared out. Like any other language, these rules are the trickiest part. There has been a lot of confusion as to where to use “Could, Should and Would” in a sentence. This article will eliminate all your confusions and queries.

Before we get started know that “Could, Should and Would” are auxiliary verbs. Auxiliary verbs, in a nutshell are those verbs which are used along with the main verb to give meaning or logic to the sentence. Auxiliary Verbs are also known as helper verbs or as helping verbs.

The Usage of Could:

The word “Could” is the past tense of the word “can”. Although it the past tense of the word “can”, the word “could” does not have the limited use of being used in sentences in the past tense. Sometimes “could” can also be used as in present tense as well.

Could is used to point out three things. First, it is used in place of can in past tense. Second, the word “could” is used to show that something is possible in future, but it is not certain. Lastly, the word “could” can also be used to state that something is possible now or had been possible in the past.


  • This summer could be hotter that last summer. (used in place of can)
  • The train could be late. (shows a possibility)
  • If we had left earlier, we could have caught the flight. (showing possibility but not certainty)

The Usage of Should:

The word “should” is the past tense of the word shall. The word “shall” in simple words can be defined as the intention of person. According to British English the word “shall” is to form future tense when used with first person. It can also be used with second and third persons also. All in all, the word “should” too expresses the strong determination of something as the word “shall”.


  • You should reach the station before the train arrives.
  • John should arrive a little after two in the afternoon.
  • Are you sure you should be playing with the healing fracture?

The Usage of Would:

The word “would” is the past tense of the word “will”. This word is usually used to express unreal situations which haven’t happened yet. The word “would” is also used to express something that has happened in the past.  And lastly the word “would” is used with certain conditions which are unreal or haven’t happened yet. These unreal situations may be wishes or situations.


  • I would love to be a professional artist. (“would” is being used in an unreal situation)
  • If I had the money, I would buy that car. (“would” is being used in an unreal condition)
  • Midway through the race, Amanda knew she would finish first. (“would” is being used in past tense)

To Summarize:

  • The words Could, Should and Wouldare a part of auxiliary verbs or helping verbs.
  • “Could” is the past tense of the word “can”.
  • “Could” can be used in three ways.
  • “Should” is the past tense of the word “shall”.
  • “Would” is the past tense of “will”.
  • “Would” can be used in three ways as well.