I know vs I knew
‘I know’ and ‘I knew’ are two expressions that should be used with difference. It is very important to know about their usage in English grammar. The expression ‘I know’ is used in the case of sentences that speak about the events that take place in the present. On the other hand the expression ‘I knew’ is used in the case of sentences that speak about the events that took place in the past. This is the main difference between the two expressions, I know and I knew.
Observe the two sentences
1. I know he studies well.
2. I knew the dog fell into the well.
In the first sentence the expression ‘I know’ indicates the knowledge of the person that ‘the boy studies well presently’. In the second sentence the expression ‘I knew’ indicates the knowledge of the person that ‘the dog fell in to the well sometime ago’.
It is interesting to note that both the expressions are often followed by the word ‘that’ before a clause begins. Observe the two sentences
1. I know that she will come today.
2. I knew that she would not come today.
In both the sentences you can see that the expressions ‘I know’ and ‘I knew’ are followed by the word ‘that’.
It is very important to know that the verb will have to be changed to its past tense form when the expression ‘I knew’ is used as in the sentence ‘I knew she made it with ease’. Here you can see that the verb ‘make’ is changed to its past tense form ‘made’ since the expression ‘I knew’ is used. On the other hand the verb takes its present tense form in the case of the use of the expression ‘I know’.