Fatal error: uncaught mysqli_SQL_exception: you

We can't help you based on that: you need to look at the code that generates and sets up the SQL query, not just the code that actually executes it.

An SQL INSERT query looks like this:

INSERT INTO myTable (myColumn1, myColumn2) VALUES (?, ?)

and you need to add the parameter values to the query when you build it. PHP MySQL Prepared Statements[^] should help.

The most common reason for an INSERT statement failing is that it's been built wrong: Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

Which SQL sees as three separate commands:

SELECT * FROM MyTable WHERE StreetAddress = 'x';

A perfectly valid SELECT

DROP TABLE MyTable;

A perfectly valid "delete the table" command

--'

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?

prepare("INSERT INTO form (first_name, last_name, mother_name, father_name, address) Values (?, ?, ?, ?, ?)");