Question

They have been working _____ two hours.
Fill in the blanks with an appropriate word.
A) Since
B) For
C) Because
D) In spite

Answer 1

Hint: Two of the options given in the question are prepositions and two of them are conjunctions. Prepositions are words that show a relation between the subject and the object or the actions of a subject and the object. Conjunctions on the other hand are words that connect two or more words, clauses or phrases into one single sentence.

Complete answer:
In the given sentence, the blank is provided between the verb and the time. Therefore, we must use a word that indicates a relation between the verb and the time. For such purposes we use prepositions.

Now let us look into the given options:
Option A) Since – The word ‘since’ is a preposition and is used to indicate the time at which an action or an event began. For e.g. He has been working since last December. He has been studying since 8 o’clock. In the question, we are not given a starting point. We are given a time span i.e. two hours. Therefore, this option is incorrect.
Option B) For – The word ‘for’ is a preposition used for indicating the purpose or the time span of an action or event. For e.g. I have come here for an interview. The program went on for almost four hours. When we use it to fill the blank, the sentence becomes “They have been working for two hours.” This option fits correctly as we are provided with a time span of ‘two hours’. Hence, it is the right option.
Option C) Because – The word ‘because’ is a conjunction and it is used to join two different clauses, that too, a clause that provides an explanation or a reason for the first clause. For e.g. I worked very hard because I needed the money. In the given question, “They have been working because two hours” does not make sense, as ‘two hours’ is not the reason for them working. This option is wrong.
Option D) In spite – ‘In spite’ is a conjunction used to join two clauses that have contrast to each other or contradict each other. For e.g. In spite of playing really well, he never made it to the finals. In the question, we do not have any contradictory statements. Therefore, this option is incorrect.

Thus, the correct answer is Option (B) They have been working for two hours.

Note: Students often get confused while using ‘since’, ‘till’ and ‘for’ in relation to time. ‘Since’ is used to tell when a certain action or event began. ‘From’ can also be used in this case. For e.g. We have been living here since/from 2019. We use ‘for’ when we want to tell how long an action or event lasts. For e.g. He slept for one hour. ‘Till’ is used to indicate when an event will come to an end. For e.g. I will sleep till 5 o’clock.