Hello Niwantha, Both sentences are grammatically correct, but there is a slight difference in meaning. In (1) "open" is an adjective. The sentence means that the office will be available to do business tomorrow (probably for the whole day). In (2), "opened" is the past participle of the verb "open." This sentence means that at some time tomorrow someone will unlock the door to the office. It's not clear if this means that the office will be conducting business, or simply that it will be possible to walk into the building. I hope that this was helpful. Christine

The first is mostly likely what you want.

“Will be open” is the best option :)

Thanks all!

Hey. The two sentences are both correct but mean different things: 'Will be opened' refers to the discrete action of opening the office. 'Will be open' refers to the status of the office over a longer period of time. To give an example of how the two might be used differently, 2 suggests that your office is still closed (and will only be opened tomorrow). By contrast, you could say 'my office will be open tomorrow' and this would be compatible with its having been open previously. Hope this is helpful and not too confusing. H