TOEFL

You can study 1 to 2 hours on weekdays. On weekends, try to do 3–4 hours if possible. But no need to study whole day. Just be regular and serious.

Yes, 8 weeks is enough if you study every day. Just follow this TOEFL study plan, do some practice tests, and focus on your weak parts. Many students do it in 2 months.

It depends. Some students find IELTS easier because it feels more real and friendly. The Speaking test in IELTS is face-to-face with an examiner, not with a computer like in PTE or TOEFL. But TOEFL has more academic-style English, and PTE gives fast results.

A TOEFL score of 100+ is considered strong for US universities. Ivy League schools may expect scores between 105 and 110.

Yes, there a book, TOEFL Grammar Guide Advanced by Timothy Dickeson that is very good for TOEFL english grammar. It is short, simple, and focuses only on grammar that comes in the TOEFL test.

Yes. If you are already familiar with the TOEFL but want to improve speaking and writing, then the book Speaking and Writing Strategies for the TOEFL iBT is very helpful.

A lot of students prefer Kaplan TOEFL iBT Prep Plus because it's easy to follow and covers everything. The book has 4 full-length tests and helpful video lessons. You can even study on your phone. 

The best book for TOEFL beginners is The Official Guide to the TOEFL iBT (the latest version).

• It is made by ETS, the people who make the real TOEFL test
• Explains every section step-by-step
• Gives you 3 full tests
• Good if you are just starting and want to know how TOEFL works

Usually, the Official Guide by ETS and Kaplan TOEFL Prep have the best reviews online. Students like them because they are clear, updated, and close to the real test. 

If your English is already good and you want a high score. Try Delta's Key to the TOEFL iBT: This is more advanced and detailed. The Collins TOEFL books are also good for improving speaking, listening, etc.