If you have already dabbled in the use of the perfect tense, you might be wondering, “When do I know which of the two auxiliaries to use?” The answer all depends on the verb you use.Most verbs in the perfect tense are perfectly happy with having ‘avoir’ as their auxiliary, but as with all other parts of language learning, there are exceptions. In this case, some verbs do not allow their auxiliaries to be ‘avoir’, but rather ‘être’.The most obvious example of this is when you want to say that you went somewhere in the perfect tense, such as “I went to the cinema.”One half of forming this sentence is business as usual: you substitute the ending of the verb for the correct past participle ending to make it a past participle. However, in the case of the verb ‘aller’ (to go) in French, along with several others, you must use ‘être’ instead.The process is the same as with avoir, you just have to use être in its place.So, to say “I went to the cinema”, you must say “Je suis allé* au cinéma”.For the remaining persons, the same sentence looks like this:- “You went to the cinema” – “Tu es allé* au cinéma”- “He/she went to the cinema” – “Il/elle est allé* au cinéma”- “We went to the cinema” – “Nous sommes allés** au cinéma”- “You (all) went to the cinema” – “Vous êtes allés** au cinéma”- “They went to the cinema – “Ils/elles sont allés* au cinéma”If you are referring to someone or something feminine, you must add an extra ‘e’ to the end of the past participle – even if you are referring to yourself. We call this agreement.With the verb ‘être’, the thing that ‘être’ is describing must ‘agree’ with the gender of what it is describing – just like how you must always ‘agree’ with adjectives.In this case, ‘allé’ would become ‘allée’For example:- A woman would write “Je suis allée au cinéma”- To talk about how a girl went to the cinema, you would say “Elle est allée au cinema”- If a group of girls was talking about how they went to the cinema, they would say “Nous sommes allées* au cinéma”- If you were telling a group of girls about how they all went to the cinema, you would say “Vous êtes allées** au cinéma”- If you were talking about a group of girls who went to the cinema, you would say “Elles sont allées** au cinéma”**If the pronoun you are using is plural, i.e. if it is either ‘ils’, ‘elles’, ‘nous’, or the plural form of ‘vous’, you must add an ‘s’ to the end of the past participle, even on top of any feminine agreement, like in the previous example.In this case, ‘allé’ would become ‘allés’, or ‘allées’, if a feminine agreement is needed.For example:- A group of people talking about how they all went to the cinema would say “Nous sommes allés au cinéma”- Someone telling a group of people that they all went to the cinema would say “Vous êtes allés au cinéma”- Someone talking about a group of people going to the cinema would say “Ils sont allés au cinéma”The question is, what verbs use être as an auxiliary?In general, verbs which explicitly describe movement (coming, going, leaving, dying, being born, returning, ascending, descending etc.) use être as their auxiliary.The following is an exhaustive list of all such verbs, and as an aide-memoire, you can refer to them as the ‘DR & MRS VANDERTRAMP’ verbs.Devenir – to becomeRevenir – to come backMourir – to dieRetourner – to returnSortir – to go out / exitVenir – to comeArriver – to arriveNaître – to be bornDescendre – to go down / descendEntrer – to enterRentrer – to go backTomber – to fallRester – to stayAller – to goMonter – to climbPartir – to leaveYou must never use ‘avoir’ as an auxiliary for these words.Another group of verbs which always takes ‘être’ as an auxiliary are those verbs which are reflexive, e.g. se lever, se laver, se demander etc.In such cases, you simply substitute the main verb which immediately follows the reflexive pronoun with the appropriate conjugated form of ‘être’, followed by the past participle of the main verb, as per usual in the perfect tense.For example:‘Je me lève’ (I get up) becomes ‘Je me suis levé’ (I got up).Note: all of the rules regarding agreement as discussed previously must also apply to perfect reflexive constructions because ‘être’ is the auxiliary in such cases.E.g. ‘Elles se demandent’ (they (the girls) wondered) becomes ‘Elles se sont demandées’