One of the things you need to get used to in French is the subject-verb-object order. In English, the pattern is SVO (i.e. subject-verb-object), e.g. ‘He is waiting for you’. In French, however, objects appear before the verb, making the order more akin to SOV. If we translate the previous example, we get Il vous attend. A mistake one could easily make in looking at this is conjugating the verb attendre according to vous instead of il since vous appears right before the verb. This will give Il vous attendez, which is incorrect because il is the subject of this sentence and the one doing the waiting, not vous.

The mistake becomes even more pronounced when we put the sentence in the passé composé: Il vous a attendu. Again, the object clings to the subject and is placed before both the auxiliary verb (a – avoir) and the past participle of the main verb (attendu – attendre). The temptation would be to write Il vous avez attendu or something similar, and at first glance it might look and sound alright. Beware of this as what sounds alright may not necessarily be grammatically correct (and vice versa). When dealing with sentences of this nature (and probability has it that you will almost always be using this structure), read over what you have written and ensure you have correctly conjugated the verb and correlated it with the right entity.

Look at this pair of sentences: Ils m’ont attendu | Ils m’a attendu. Which one is right? What is your reasoning for choosing that one?