#1 has incorrect grammar. For the most logical fix, maintaining a consistent tone throughout the sentence, change "was become" to "had become". Alternatively, you could change "was become" to "became" but that would leave the sentence with a messy change of tone in the middle, so I don't recommend this option. After this correction, #2 would have the same meaning as #1. #3 has incorrect grammar. To fix it in the most obvious manner, remove the word "been", or remove the word "become". Leave just one of these words. They have slightly different meanings so I can not tell you which one to remove - it depends on your intended meaning. To clarify: * WAS and HAD BEEN have equal meaning but different tone to each other. * BECAME and HAD BECOME have equal meaning but different tone to each other. * WAS and HAD BEEN are similar but not equal in meaning to BECAME and HAD BECOME. Because WAS and HAD BEEN refer to a singular static status, while BECAME and HAD BECOME refer to a change of status. To clarify, if you heard that HAD BEEN sleepy yesterday, you would only know that I were sleepy at some point in time yesterday - it may have been all day, or for a brief moment. But if you heard that I HAD BECOME sleepy yesterday, that implies there were a time yesterday when I were not so sleepy, then I changed, becoming sleepy, all within that day.

1. "Was become" does not make sense. Replace it with "had become". In general, it is not wrong to follow "was" with a past participle. For example, you can say "The song was sung." That works because it is possible to sing a song and "sung" acts like an adjective: the song is a "sung song". However, in your sentence "become" cannot act as an adjective. The headmaster is not a "become headmaster". That wouldn't make sense. 2. This is grammatical and makes sense but "had become" works better. It would also be better to simply say "...that the headmaster was too deaf ..." 3. This is not grammatical. Eliminate "been". To use "been", you could say "...that the headmaster had been becoming ...", but it would be even better to say "...that the headmaster was becoming..." 4. good

Hey, only number four is correct. The writer describes something in the past (with past simple), then an older past event (with past perfect). This is a good technique if you want to describe two past events in reverse order: first the more recent one, then the older one. What's wrong with the others? 1 - 'was become' is not possible, at least in modern English. 2 - This doesn't make logical sense, because past perfect was used for the more recent event (the problem being obvious), not the older event (the deafness problem starting). 3 - 'had been become' is not possible