Formal and written Thai words

-ing, -tion: turns a verb into a noun (the act of …)

-ness (turns a verb or adjective into a noun)

person (who …): makes words for people, like -er

-er, -ist: someone who does it (as a job or a passion)

which, who (adds information; formal, written)

when, once (formal)

so, therefore (before the verb of the result)

various, all kinds of (after the noun)

may, might (written)

to lead

to be able to, can (formal)

of (in formal names)

to receive, to get (formal)

which, any (formal)

to meet

to be involved, related, concerned (with)

you, he, she (respectful)

doctor, physician (formal)

to say, to state (formal)

the said, the … in question (formal)

to consider, to look into (formal)

to do, to commit (an act) (formal)

within, inside

to propose, to offer, to put forward

to carry out, to perform

tend to, usually (written)

how, in what way (formal, written)

or not

due to, because of (formal)

however, nevertheless

case

type, category

to proceed, to take action

to know (polite, formal)

I, me (women, formal)

to guarantee, to certify

no matter (what, who, where …), regardless of

that said

as well as, including

namely, which are (introduces a full list)

apart from, besides

moreover, in addition, besides this

etc., and so on (after a list)

as follows, like this (formal)

later, subsequently (in a story)

while, as (formal)

the present

that is (to say), i.e.

generally, in general

directly, in person

extremely, very much (formal)

naturally, is bound to (formal)

not, did not (formal)

at, in (formal: places and dates)

to appear, to show up

to consist of, to be made up of

to edit, to correct, to fix (formal)

to live, to reside (formal)

to analyse

to help, to assist (formal)

to check, to verify, to inspect (formal)

to specify, to state, to identify

to promote, to encourage, to support

to meet with, to experience, to face (formal)

to affect, to have an effect (on), to result (in)

to reveal, to disclose

additional, further, more (formal)

to pay, to settle (formal)

to sell, to distribute (formal)

to consume, to eat (formal)

to eat (polite)

to hand over, to present, to give (formal)

to wish (to), to want (formal)

to approve, to authorise

still, continue to (formal)

she, her (in novels; old-fashioned)

mind, heart, spirit

business day, working day

per cent (formal: before the number)

without, -less (formal)

condition, terms (a requirement)

purpose, objective (formal)

father (formal: forms, documents)

mother (formal: forms, documents)

child, son or daughter (formal)

to marry

sufficient, enough (formal)

fact, the facts

head (formal, polite)

pleased, glad, happy (to)

likewise, similarly

to log in, to sign in

characteristic, appearance

these (formal; after a noun)

altogether, in total

to enquire, to ask (formal)

to use a service, to be a customer

Dear … (at the top of a letter)

under (a rule, a condition, someone's care)

to consent, to agree (to), to allow

to cause, to give rise to (formal)

to claim

to assess, to evaluate, to estimate

pure, nothing but

like this, such (formal)

to survey, to explore

firstly, first (in a formal list)