'Buy' versus 'bought'

[Emma]

English Grammar Tests, Elementary Level

ESL/EFL Test #107 "Irregular Verbs (1)", question 10

Luther has to ......... four new tires for his car. He wants higher quality tires so they will last longer.

(a) bought
(b) buying
(c) buy

English Grammar Tests, Elementary Level

ESL/EFL Test #107 "Irregular Verbs (1)", answer 10

Luther has to buy four new tires for his car. He wants higher quality tires so they will last longer.

Correct answer: (c) buy
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when i write bought?

Emma

[Linda]

Hello,
You should use 'bought' in the past tense. 'Buy' is the present form and 'bought' is the past tense. This is an example of an irregular verb.
Take care.
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