Part of speech for "please" followed by a verb

I know that "please" can be many different parts of speech; interjection, an adverb, or a verb, depending on how it's used. I'm looking specifically to find out what part of speech "please" is when followed by a verb:

• Please send me your information
• Please find your shoes
• Please write down your name

It is an adverb, according to Merriam-Webster.

In your case, it is used as a function word to express politeness or emphasis in a request.

Traditional grammar doesn't really have a category that "please" would fit into very adequately. So like various other words, it tends to get dumped into "adverb" or "exclamation" that tend to be used as "dustbin" categories for words that don't really fit anywhere (cf "yes", "viz"...). But there's really little rationale in lumping the word "please" with, say, the word "carefully".

I would suggest using a framework that allows a broader set of categories, or which at least admits as additional categories words like this that are essentially "isolates" that don't readily fit into one of the regular productive categories.

The British National Corpus tagset, for example, has a category ITJ for "Interjection or other isolate" (which is also a bit of a dustbin, but more satisfactory than lumping any old word into "adverb"-- at least it's effectively admitting "category for words that basically don't belong anywhere").

You might also want to consider having categories for words that effectively 'stand in for' whole clauses or phrases. So, e.g. just as you might analyse "soon" as effectively a prepositional phrase (i.e. you see it as effectively a placeholder for e.g. "in a moment", "in a few minutes", "within two days"), you might analyse please as, say, a verb-phrase placeholder.

Or, put another way: there's no single "right" answer and it depends on your analysis. But if you call it an "adverb" as many dictionaries do, you may want to try and be clear with yourself what similarity you think 'please' actually has with more canonical examples of "adverbs" and how well it really fits.

The classification of please as an adverb is, I believe, ridiculous. It can appear in similar positions in sentences (Will you please / kindly / quickly fasten your seat belts - where I believe kindly is not acting as an adverb either – contrast Will you kindly speak to those people who have just seen their dog run over with Will you speak kindly to those people who have just seen their dog run over) - but is being used as a discourse element extra to the semantics of (the rest of the) sentence, whilst usage allows it to be included between the capital letter and the full stop. It is almost the equivalent of an accompanying smile.

This usage of please is, to add to the response number 5 above (sorry, I can't fathom out to whom to accredit it!), a discourse marker subclass politeness (or emphasis if used with irony) marker.

(I've come across this terminology on various websites, and don't know how widely the terms are accepted - or indeed, how widely the courage to sensibly confine the adverb class to words that are truly modifying verbs is to be found.)*

Very kindly would be a two-word variant of kindly; I'd classify it as a single lexeme. Pretty please is similarly a variant of please, but has whimsical or childish overtones, and must occur at the start or end of the request.

• I've been looking for a more sensible approach to word-classes, largely on the Internet, for years now. There still seems to be a lot of argument over where to lump and where to split classes even (or especially) between different linguistics departments. This sadly leaves us saddled with the sacrosanct but untenable 8 classes of antiquity, with people claiming this view as Gospel, with no clear voice suggesting any better alternative.

I've compiled a list as a working model (sorry I can't format better):

Noun

Verb
Adjective
Adverb
Pronoun
Auxiliary
Determiner
Preposition
Adverbial Particle and other Particle components of multi-word verbs
Conjunction / Coordinator
Subordinator
Complementiser
Degree/Secondary Modifier
Limiting Modifier
Determiner Modifier
Prepositional Phrase Modifier
Negator
Infinitive Marker
(Sentence connector) . . . (Sentence Adverb) . . . Discourse Marker
Interjection (Nonsense word) (Lyrical filler)

Pro-sentence / Sentence Substitute

and am prepared to consider idioms, open compounds etc as single units (eg He who must not be named; ship of the desert; take off (of a plane); let go; make do...