referring to an action
You use already to say that something has happened before now, or that it has happened sooner than expected. When referring to an action, most speakers of British English use a perfect form with already. They put already after have, has, or had, or at the end of a clause.
He had already left when I arrived.
I've had tea already, thank you.
Many speakers of American English, and some speakers of British English, use the past simple instead of the present perfect. For example, instead of saying ‘I have already met him’, they say ‘I already met him’ or ‘I met him already’.
You already woke up the kids.
I told you already – he's a professor.
referring to a situation
Already is also used to say that a situation exists at an earlier time than expected.
If there is no auxiliary verb, you put already in front of the verb, unless the verb is be.
She already knows the answer.
By the middle of June the society already had more than 1000 members.
If the verb is be, you put already after it.
It was already dark.
Tickets are already available online.
If there is an auxiliary verb, you put already after the auxiliary verb.
This species is already considered endangered.
If there is more than one auxiliary verb, you put already after the first one.
Portable computers can already be plugged into TV sets.
You can put already at the beginning of a sentence for emphasis.
Already the company is three quarters of the way to the target.