This is the 1246th most frequent French word.
acheter
To buy.
Here "acheter" is used in the infinitive form as part of the construction with the auxiliary verb "aller" to express a future intention.
Je vais acheter une nouvelle voiture.
I'm going to buy a new car.
In this sentence, "acheter" is conjugated in the present indicative tense to describe a habitual action.
Elle achète du pain tous les jours.
She buys bread every day.
Here, "acheter" is conjugated in the past tense (passé composé) to indicate a completed action in the past.