mysql() refuses to read characters in php -

i copied code word database causing problems when want retrieve them mysql() in php. i've identified problem is, dashes 1 causing error retrieving it:

tue – thur:  

i have convert dash following 1 in order mysql() able retrieve it: (it's unnoticeable causes error took me time figure out happening)

tue - thur:  

this causing error:

it’s 

but not one:

it's 

this 1 causing problem:

course…much more! 

i have change one:

course...much more 

because had copy huge amounts of text database hard me spot part of text causing problem. looks identical. so, question is, knows tool or can use paste text , me either point me problematic characters or change them ones won't cause problem?

note

now know in order fix have change encoding of string i'm inserting database unicode utf8. there idea how can string converted?

to convert unicode string utf8 discovered php function utf8_decode after pass string unicode characters, weird character set "?" can identify them easier.