No. It should be two sentences
1. Pierre never studies.
2. He is making a mistake ... etc.
Yes, except it is actually two sentences: "Pierre never studies. He is making a mistake if he thinks he will have a good grade on the test."
Also, I would use the word "get" instead of "have." I don't think "have" is grammatically incorrect or anything, but most people say "get a good grade" not "have a good grade."
So then it would be: "Pierre never studies. He is making a mistake if he thinks he will get a good grade on the test."
I will amonish Larry for making a mistake.
I don't want to "mistake" your kindness for weakness. If you "mistake"my intention,you are making a mistake. You must have "mistaken" me for someone else.
Replace the words "be making" with "make."
The boss called his assistant a nincompoop for making such a careless mistake.
He studies the newly discovered spider.My studies included sociology, information technology and forensic psychology.The assassin studies his target before making a move.
What it means when you speak a spoonerism is you are changing the letters around in the sentence to make light of a subject or when you are making a mistake.
A mistake is something done in error. For instance, if you dial the wrong phone number, you made a mistake.
no
Whatever experiment scientists do, when they make a mistake they obviously need to do the whole experiment again!
Ancient and common wine-making mistake.
you are making a mistake - you are in the wrong
no