Learn Spanish (Latin America): Viajo contigo porque tengo una invitación. - I am traveling with you because I have an invitation.

In Spanish, the preposition con (with) combines with the informal 'you' pronoun to create a special, single word: contigo. You will never say 'con tú' or 'con ti'. Another common one you will learn in this lesson is conmigo, which means 'with me'.

Where is the word for 'I' in this sentence?

In Spanish, the endings of the verbs usually tell you who is doing the action, so you do not need to say 'I' (yo). The verbs viajar (to travel) and tener (to have) change to viajo and tengo when you talk about yourself. You could say Yo viajo, but it is standard to drop the yo.

I have seen 'why' translated as por qué. Is porque related?

Yes! When written as two words with an accent mark, por qué means 'why' and is used to ask questions. When written as one word without an accent, porque means 'because', which is what we use in this sentence to give a reason.

How do I know to use una instead of un before invitación?