Three future-form slips
one wrong word breaks the sentence
Each future form has its own pattern. One extra word, or one missing, and the sentence breaks.
Tomorrow I am going to visitsbase verb: visit the campus. I will to phoneno 'to' after will my parents, and as soon as I will arriveno 'will' here I will send a message.
IELTS Band 8 descriptors mention a majority of error-free sentences.