Made him dig or Made him dug?

In a situation where we have two lexical verbs with one functioning as the main verb and the other as an auxiliary verb, the first verb in the complex will serve as an auxiliary verb accounting for tense and number while the second verb will function as a main verb and be in its base form. The base form of a verb is that which has not been inflected. For example, let us LOOK at the following:

Base Form/Present Plural Form	Present Singular Form	Past Tense Form	Past Perfect Form	Continuous Form
Dig	Digs	Dug	Dug	Digging
Begin	Begins	Began	Begun	Beginning
Play	Plays	Played	Played	Playing
look,	Looks	Looked	looked	Looking
Walk	Walks	Walked	walked	walking

Let us look at the following examples:

1. LET us BEGIN (not  beginning, began, begun or begins) to worship God.

2. She MAKES him PLAY

3. We MADE him LOOK at the boy

4. She LETS him WALK on the lawn today.

5. John MADE him DIG the hole.   

The verb phases which are split in the above sentences are:

1. Let (auxiliary) begin (main)

2. Makes (auxiliary)  play (main)

3. Made (auxiliary) look (main)

4. Lets (auxiliary) walk (main)

5. Made (auxiliary) dig (main)