Learning a new language can be challenging.
She was grumpy today, but she can be very pleasant when she want to be.
With a positive attitude, any day can be a good one.
8-10 sentences
you are going to need six or eight sentences for you application
they need to be balanced
You need to learn the rules of English grammar to be able to correct sentences.
NO
Most sentences will not need both "and" and "then" in order to be a complete sentence. Either "and" or "then" can be used to join sentences together when needed.
I need an answer in 3-5 sentences
8
you need something better to do with your time
Complete sentences
Here's one: DO YOU REALLY NEED ME TO GIVE YOU SENTENCES FOR YOU? NO, REALLY, I MEAN IT!
When forming tenses of words.