1. I'll send you a postcard when I am on holiday.
2. I wish it would have been warmer.
3. I am going to the party unless you stop me.
Every sentence must start with a capital letter and end with the appropriate end punctuation. The personal pronoun I is always a capital letter.
So and very can have the same meaning insome cases.
Keep working on the basics like subject-verb agreement (are these sentences correct), capitalization and punctuation. Hard work and practice are two of the keys to success, another is asking for help when you need it.
Student or Learner