Infinitive vs finite verbs.

[Hamids]

Hello,
could anyone throw some light on their meaning an use in sentences.

[Mister Micawber]

This is far too broad and vague a question, Hamids. Do you have a specific sentence that troubles you?
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Native English teacher at Mister Micawber's

[Hamids]

Sorry sir, basically i am confused about sentences like
Let + object form of pronoun + verb

Let him do/speak.
in these sentences verb does not change with pronoun like
let him makes his own drink.
please also point out if iam identifying verbs and objrcts in correctly

[Mister Micawber]

Let him speak.

'Let' is the finite verb, so it changes with the person:

I let him speak.
She lets him speak.

'Speak' is a bare infinitive (i.e. no 'to') and therefore does not change with the person:

I let him speak.
I let them speak.
I let you speak.

Is that enough information, Hamid?
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Native English teacher at Mister Micawber's

[Hamids]

unusual arrangement of words(please suggest correct word)
let him speak:
let = verb
him= object
speak= role?

[Mister Micawber]

Sorry, I don't know what you are looking for. It is a normal arrangement of words:

He made her leave.
I let him borrow my car.
She had them wash her poodle.

'Made' is the finite causative verb; 'her' is the object of 'made leave'; 'leave' is a nonfinite verb complement, I suppose.
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Native English teacher at Mister Micawber's

[Hamids]

thank you sir,
'Made' is the finite causative verb; 'her' is the object of 'made leave'; 'leave' is a nonfinite verb complement, I suppose.

actually i was confused about that sentence having two verbs, let and speak, now as suggested speak should be nonfinite verb complement