1. You had lunch already.
2. You already had lunch.
3. You have already had lunch.
4. You have had lunch already.
---------------------
Are they all grammatical and the same in meaning? Which one is commonly used?
All are correct and, yes, they all mean about the same thing. I'm not sure any of them is more commonly used than the others.
on / still / you / can / help / Saturday / me / ?
All four sentences are grammatically correct, and they have the same meaning. They all express the idea that the person in question has already eaten their lunch. However, there are slight differences in terms of emphasis and word order.
1. "You had lunch already."
This sentence follows a subject-verb-object (SVO) word order and places emphasis on the action of having lunch already. It is a straightforward statement.
2. "You already had lunch."
This sentence also follows an SVO word order and places emphasis on the adverb "already." It highlights the fact that the person has already had lunch, possibly suggesting surprise or the need to clarify.
3. "You have already had lunch."
This sentence follows the present perfect tense, combining "have/has" with the past participle "had." The word "already" emphasizes that the action of having lunch occurred in the past before the present moment. This form is commonly used in spoken and written English.
4. "You have had lunch already."
This sentence follows the present perfect tense but places the word "already" at the end. While the exact emphasis can vary, it generally conveys the notion that lunch has been consumed before the time of speaking or writing.
In terms of common usage, sentences 3 and 4 are more commonly heard and read in both formal and informal contexts. However, all four variations are grammatically acceptable and may be used interchangeably depending on personal preference or specific contexts.