Yes guests' is the grammatically correct possessive plural of guest. For example, "Take the guests' coats and put them in the bedroom."
My teachers tell me that it's not. It's grammatically correct to say for instance. Take this as an example: For instance, this is my turtle.
It is grammatically correct, but still wrong. Use "make a commitment."
You had not taken that into account. Would be the grammatically correct version of that sentence.
Yes, it is perfectly valid.
Its problem is not grammatical, but idiomatic. We say take an exam, or sit for an exam, but we do not say attend an exam. A sentence may be grammatically correct and still wrong.
Yes, except that "meeting" is misspelled.
The first statement uses incorrect grammar, the second is grammatically correct.
Teachers give tests. Students take tests.
they take it as their duty and commitment to provide a world-class
Take care of, or work on, would be better put.
This question is not grammatically correct enough to make sense of. Therefore, it is not possible for me to provide an appropriately formed answer to it.