1) функция инфинитива, как обычного глагола. To think - думать. (В контексте: Ньютон начал думать.) ( Составное глагольное сказуемое)
2) инфинитива используется как замена подчинительному союзу'чтобы'. (Функцию союзная)
3) Союзное значение.
Скорее всего это количество слов
A good way -IS- to study English ...
The plus - IS- on the Internet ...
Also you - MAY NOT-
One more plus -IS- that you - DON'T- spend money on that.now each person can alow it to himself
Больше не успела проверить
Большими буквами ошибки
Reporter : good evening johnny good to see you
Johnny : Good evening
Editor : I'm a magazine editor, going to write about you write an interview as you visited the children's hospital
Johnny
Yeah ,in my spare time I visited the children's hospital where they
treat sick children . I wore a pirate costume and it pleased the
children . We were photographed with them and played
Editor : This is not the first time you visited the hospital
Johnny : Yes , I donated money and invited the doctors to my movies
Editor: Thank you johnny for the interview
Johnny : Not at all ! Always contact !