Question

Select the appropriate option to fill in the blank-
If I _ _ _ _ _ his number, I would phone him. (Know)
a) Knew
b) Known
c) Has known
d) Has been knowing

Answer 1

Hint: The three verb forms of ‘know' are – know(infinitive), knowing(present participle), knew(past tense).

Complete answer:
You must read the sentence carefully, and try to detect the tense used in the given sentence. Try to match your answer with that verb form. The given sentence is a Sort 2 conditional. It expresses a theoretical condition 'In the event that I (know) his number' and its plausible outcome 'I would telephone him'. In this sort, the if-statement is in the basic past tense, and the fundamental provision is in the current restrictive tense 'would telephone'.
Now, let us examine all the given options to find out the correct answer :
Option ‘a’ is Knew. It is the past tense of ‘know'. It is a simple past tense verb which will best suit in the given blank of the given sentence. The sentence will also make complete sense when it is filled in the blank.
Option ‘b’ is Known. It cannot be filled in the given blank, it will not make any sense and would be grammatically incorrect. So, we will eliminate this option.
Option ‘c’ is Has known. It is in the present perfect tense which will not fit in the given blank. So, we will eliminate this option as well.
Option ‘d’ is Has been knowing. It is in present perfect continuous tense which cannot be used in the given blank. So, this is also an incorrect option.
As we have analyzed all the given options, we can easily figure out the correct option. Here, the appropriate option to fill in the blank is – knew. Hence, the complete sentence would be – If i knew his number, i would phone him. Hence, the option ‘a’ is the correct option.

Note:
All the other options are plausible distractions. You must know the correct verb form of the sentence, and then match your answer with that exact same verb form.