Question: ```
def my_method(parameter)
  if <what should be here?>
    puts "parameter is a string"
  elsif <and here?>
    puts "parameter is a symbol"
  end
end

```

Answer: 
```
def my_method(parameter)
  if parameter.is_a? String
    puts "parameter is a string"
  elsif parameter.is_a? Symbol
    puts "parameter is a symbol"
  end
end

```

should solve your issue
```
if parameter.is_a? String
  puts "string"
elsif parameter.is_a? Symbol
  puts "symbol"
end

```

I hope this helps.