One possible solution is:
18 = 44 x .4 + .4
4x4+4-square root of 4=18
(4/.4)+4+4 or (44x.4)+.4
4 - (4/4 x 4/4) or 4 + 4 - 4 - 4/4
(4x4+4) / 4=5
44 * 4/4
{4! - sqrt(4)}/.4
4/4 + 4 × 4/4
4*(4! + 4/4)
(4!/4)4 - 4
4+4(4-4)
4*4+4/4 = 17
4*4*4-(4/4)