Is the Past Participle of 'buy' bought?

Answer 1

You're thinking of the past tense of the word "buy". The past participle of buy would be has bought or had bought. The differences between past tense and past participle are listed below:

A past participle ends in -ed or -en and it has two functions:

1) Adjective

EX: This car is heated. (Verb: "is"; Adjective "heated")

EX: We had a heated argument. (Adjective "heated")

As an adjective, the past participle occurs after the verb BE (is, am, was, were, been) or it modifies a noun.

2) Part of a verb

EX: The stove has heated the room. (Verb: "has"; Part of a verb: "heated")

As a part of a verb, the past participle occurs with the verb HAVE (have, has, had).

Past tense refers to a verb. (Please note that, past participles are not verbs.)

EX: The stove heated the room.

In the example above, the word 'heated' doesn't do the following things:

It doesn't occur with BE (is, am, was, were, been)

It doesn't occur with HAVE (have, has, have)

It doesn't modify a noun (argument)

"Heated" functions all by itself. It's a verb, and the -ed ending tells us it's a past tense verb.