COD ou COI?

Bonjour! Ça va?

Today, our topic is "COD ou COI?". First, you need to know what they are. 

COD = Complément objet direct (me, te, le, la, nous, vous, les)

COI = Complément objet indirect (me, te, lui, nous, vous, leur)

In English, objects follow verbs. In French, it may not be the case. If we want to use pronouns instead of mentioning the names / nouns, we need to put the object pronouns before the verbs.

COD

Est-ce que tu vois tes parents après le cours?

Non, je ne les vois pas. 

In the question, "tes parents" is the direct object and goes after the verb "vois". In the answer, we don't want to mention "parents" again, so instead of using "mes parents", we use the object pronoun "les" which should be put before the verb "vois". 

Pay attention to the structure of a negative sentence. The order goes in this way:

sujet + ne + pronoms + verbe + pas

COI

Est-ce que vous écrivez à vos amis quand vous êtes en vacances?
Non, je ne leur écris pas.

"à vos amis" is the indirect object (because there is a preposition) and goes after the verb "écrivez". Again, we don't want to mention these three words, so we use the pronoun "leur" and put it before the verb "écris".  

La température, ça vous va?

Oui, ça me va.

"vous" and "me" are COI and they come before the verb "va". (Attention: "va" here does not mean "go". The two sentences mean "Does the temperature suit you?" "Yes, it suits me.")

Why are they COI?

It is because the verb "aller" is used with the preposition "à": une chose + aller + à une personne

C'est tout! Salut!