Hello,
If I want to say
" I have sent out your order on last Thursday of Spt.24." is this the correct grammar? do I need the "on" before "last Thursday"? How do I say this correctly?
Thank you
Using "on" is optional. However, the sentence is correct if you say or write, "I sent out your order last Thursday, which was September 24th."
Here are a few considerations:
1. Use the simple past, not the present perfect, because you are referring to finished time.
2. Saying "last Thursday" already specifies a date, so it's slightly redundant and a little awkward to include both "Thursday" and "September 24th" in the same phrase. This is why I included "September 24th" in a "which" clause as added information.
3. The phrase "Thursday of September 24th" is not right because "Thursday" is not part of the date "September 24th". You could say "on Thursday, the 24th of September". And in this way, not using a "which" clause is okay because you are not specifying a specific Thursday, which, of course, means that you are not specifying a specific date by saying Thursday. This makes it so that using "Thursday" and "September 24th" in the same phrase, separated by a comma, work well and not sound slightly redundant or awkward in the least.
To conclude, here are two example sentences that I recommend using:
I sent out your order on Thursday, September 24th.
I sent out your order last Thursday, which was September 24th.