first lines of children's rhymes

[paris81]

The letters represent the first line of a children's rhyme

1) M M S T A N S

2) T M W I A H T S

3) O T T F F O A C A F A
Any help please really stuck

[spitza]

one two three four five once i caught a fish alive

[swannbaker]

My mother said that I never should .

[paris81]

Thanks Swannbaker
Thats what i thought but there was an A where it should have been an I

[swannbaker]

Likewise then for question 3 . Could this be a theme that's running through the quiz ? P W T Y G A T W .