gan

sory, i'm newbiew old want to instant critical me

hi gan agan all,

i have the problem sentences in novel

Co-workers ignored each other and hid behind locked doors.

i want to asking, the sentences below :

Co-workers ignored each other and hid behind locked doors.

1.what is grammar? i don't understand, or is there other than grammar and the meaning of sentences

2. and my question above is the sentences : i want to asking, the sentences below , and such as whether to use the phrase the question of formal or informal conversation ?

3. is it relevant to the language used in everyday?
please the correctly all the sentences,because i make translate google, thanks in advance (what is the formal letter)