Hi Mariaam,
Thank you for your post. One other element I wish to bring into the conversation is potential differences in subtext:
"My friend promised me that he will phone as soon as the plane arrives." - This option is more objective and definitive in restating the speaker's understanding of what has come before.
"My friend promised me that he would phone as soon as the plane arrives." - This option is more subjective, as "would" may transform this into a hypothetical or conditional statement. Accordingly, the expected outcome of the plane arriving on-time and the phone call being received may have changed or may not occur. The sentence may also convey uncertainty, such as fear or anxiety, more successfully than the alternative.

Jonathan B.
06/30/25
Mariaam K.
No this is the full sentence there was 2 more given options for answers but I know they are wrong so i just isolated the two options that l’m sure that they are definitely wrong but yeah this the full sentence06/30/25

Jonathan B.
06/30/25
Mariaam K.
Hi!! Thanks for responding and i understand what you mean but if you have to choose between these two options which one is more grammatically correct??06/30/25