Questions

Garbage truck.

It’s true, a garbage truck has 4 wheels and lots of flies because flies like garbage. Here flies means insects like houseflies, mosquitoes, ... It doesn't mean that it flies in the air.

Yaounde is the capital of Cameroon

soundex()
The soundex() function calculates the soundex key of a string. A soundex key is a four character long alphanumeric string that represent English pronunciation of a word. he soundex() function can be used for spelling applications.
< ?php
$str = "hello";
echo soundex($str);
? >

metaphone()
The metaphone() function calculates the metaphone key of a string. A metaphone key represents how a string sounds if said by an English speaking person. The metaphone() function can be used for spelling applications.
< ?php
echo metaphone("world");
? >