You need hyphens between the numbers (no spaces)

20 twenty
21 twenty-one
22 twenty-two
23 twenty-three
30 thirty
33 thirty-three
34 thirty-four
40 forty (drop the 'u' four - fourteen - forty)
44 forty-four
45 forty-five
50 fifty (five - fifteen - fifty)
55 fifty-five
56 fifty-six
60 sixty
66 sixty-six
67 sixty-seven
70 seventy
77 seventy-seven
78 seventy-eight
80 eighty
88 eighty-eight
89 eighty-nine
90 ninety
99 ninety-nine
100 a hundred/one hundred
121 one hundred and twenty-one
440 four hundred and forty

453 four hundred and fifty-three

1000 one thousand

1500 one thousand five hundred or fifteen hundred

5050 five thousand and fifty

30,000 thirty thousand