Si el Español y el Portugués son lenguas romances y su origen es el Latín. Pero el Portugués tiene bastante diferencia en la pronunciación con el Español. Sin embargo para los latinos es fácil entender el Portugués que se habla en el Brasil, y de hecho los brasileños aprenden fácilmente a hablar Español, no ocurre lo mismo en sentido contrario, porque a los que hablamos Español nos cuesta un poco de trabajo la pronunciación del Portugués.

Yes, Spanish and Portuguese are quite similar. I do speak Spanish and could understand Portuguese ,almost whole sentences, but it doesn't mean I can pronounce it correctly nor speak it or write as well. It needs to be studied then,but it will be an easier task for a Spanish speaker and the other way round. As for Italian and Spanish ( and French as well) they do have lots of similarity , yet lesser than that of both Spanish and Portuguese.

The only relationship between these languages ​​is that they are Romance languages. For this reason it's possible to understand some things that are expressed similarly in Spanish, Portuguese or Italian. But I must tell you that if you speak portuguese, you will not understand from the beginning fluent Spanish. Any way I say it's easier to a Portuguese speaker to understand Spanish than on the contrary. The Spanish language has an open and sonorous pronunciation, and this makes it more easily to be understood.