The passive and causative

verb to be in the appropriate tense + past participle of the main verb

have + object + past participle

verb to be + past simple

modals and infinitive

future simple

present perfect continuous,past perfect continuous

past simple and past perfect

when the person who carries out the action is unknown, unimportant or obvious from the text

when we want to make statements more formal or polite

when the person who carries out is important

Many local gardens are invaded by Japanese knotweed

Many local gardens are being invaded by Japanese knotweed

Many local gardens have been invading by Japanese knotweed

Many local gardens will be invaded by Japanese knotweed

The starters have already been served

The starters were already being served

The starters will be served

The starters can be served already

Two climbers can be injured in an accident tomorrow

Two climbers are being injured in an accident yesterday

Two climbers was injured in accident yesterday

Two climbers were injured in an accident yesterday

have + object + past participle

to be + object + past participle

have + object + past simple

to be + object + past simple

when we want to say that we arrange for somebody to do something for us

when we want to say that we are happy

I has already mine done

I have already had mine done

I had already mine done

I has been already done mine

You should have it looked at by a doctor

You should had looked it by a doctor

You should may have it by a doctor

You should have been it looking at by a doctor

Tony had been having his medicine prescribed

Tony will have his medicine prescribed

Tony had his medicine prescribed

Tony is having his medicine prescribed

When did Ann fridge was delivered?

When did Ann has been having her fridge delivered?

When did Ann had her fridge delivered?