Question

Fill in the blank with a suitable option:
They ____________ the dishes when she left.

• A. was washing
• B. were washing
• C. are washing
• D. have washed

Answer 1

The correct option is B were washing

The given sentence states two actions 'wash the dishes' and 'she left'. The latter action is in the past, hence the former must be relevant to it.
'When' means 'upon or after which', and introduces an action that happened just after the first action took place 'wash the dishes'.
Option B: 'Were washing' indicates the past continuous tense. It states a continuous action that happened in the past. It's the most appropriate tense form, as it is in sequence with the other action 'left'. Hence option B is correct.
Option A: 'Was washing' is incorrect here because 'was' is a singular verb, whereas 'they' is a plural noun. (The verb must agree with the subject 'they' in terms of person and number.) Hence A is incorrect.
Option C: 'Are washing' indicates a present continuous action. But the action in the given sentence is in the past, as suggested by the action 'left'.
Hence C is incorrect.
Option D: 'Have washed' is in the present perfect tense. It states an action that has just completed. But, it does not form a logical sequence with the other past action. Hence option D is incorrect.