With a regular keyboard you do it via pressing ALT and a numeric combination using the numeric keypad found on the right side of your keyboard. I'll use the word for boy in Spanish as it uses the popular letter "ņ".

So to write niņo you'd have to first have to activate the NumLock by pressing that button on your laptop, on some laptops you have to press FN + NumLock. Once the NumLock light is on you press alt + a number combination. So in this example you'd type ALT 1 6 4 and it should produce ņ which will allow you to write words like niņo.

I hope this helped as many users with laptops find this process confusing.