Level: intermediate

We can use a modal verb with have and a past participle:

Subject Modal have Past participle  
They will have arrived by now.
You might have seen the film.
Jack and Jill would have been late.

We use a modal verb with have:

  • to refer back from the present:

It's nearly eight o'clock. They will have arrived by now.

  • to refer back from a point of time in the past:

We were very worried. We thought someone might have taken the car.

  • to refer back from a point of time in the future:

We won't eat until they arrive. They might not have had supper.

  • to refer to past time:

You should have helped her when she asked.
They might have got lost. Nobody knows where they are.

Modal verbs with have 1


Modal verbs with have 2




okay, I read the advice. Form what I understood, we use "could + infinitive when we talk about a general possibility in the past and could + have + past participle when referring to specific possibilities in the past.
Any other secret meanings?


If I'm talking about an event in the future that is sort of 50/50 might or might not happen, should I use Conditional one or two?

(1) if low-lying nations are to be wiped off the map due to rising sea levels, it will have repercussions
(2) if low-lying nations were wiped off the map due to rising sea levels, it would have repercussions
(3) if low-lying nations are to be wiped off the map due to rising sea levels, it would have repercussions – this makes the most sense to me, as the first part in the present tense indicates probability, and the second part in the past tense indicated a conservative approach to it, but I guess it's not grammatically correct...

Many thanks

Hi deliciriouswombat,

Either (1) or (2) is possible. We don't mix real and unreal meanings in hypothetical sentences, so (3) in not standard English. Which of the first two options you choose is up to you. If you wish to emphasise that you see the condition (the first clause) as a real possibility then you choose (1); if you wish to emphasise that it is unlikely, impossible or purely hypothetical then you choose (2). It is not a question of probability per se, but rather the speaker's intention, and how they wish to express it.

Best wishes,


The LearnEnglish Team

Could you please explain to me, when to use the construction of modal verb + infinitive, to express past action
and when nodal verb + have + past participle again for past actions and events?

Hello Antara111,

Please read through our different modals pages (e.g. can, could and could have) for more explanations and for examples of how modals + have + past participle are used. After you've done this, feel free to ask us again, but please make your question as specific as possible.

Best wishes,
The LearnEnglish Team

Hello teachers. Some time ago i asked and i have obtained the answer. Now i have sentence: 'I knew I should do something' by the context, it action was in the past. Here the writer also wants to make it more real for us by taking us in the past and show us that action from there? As if we are with that person?

Hello rewand,

Yes, that's correct – it's as if the writer if sharing their thoughts with us from that time so that we are pulled into the story.

Best wishes,
The LearnEnglish Team

Hello, i hope i don't put you to much work with my several questions.Regarding the explanation above i'd like to finally to understand the use of modal verbs when i create a clause in the past it follows: Jane said that she would back me up if i complaned about (with) our headmaster.When i traslate in italian i can have two meanings :one in the future and othe one in the past...because i not might say as it follows: jane said that she would have backed me up if i'd complained about (with) our headmaster didn't she?
thank you in advance.

Thanks man.

could you please tell me whether we can use all perfect modals to indicate an action that finishes before another action in future-future perfect-or not?
for example:
1.by next year,i will have finished my study.
2.by next year,i might/may have finished my study.
3.by next year,i must have finished ...
4.by next year,i should have finished ...
by next year, i could/can have finished ..
if yes,please tell me the difference between could and can and the difference between may and might for showing future perfect.

best regards