Here is a current tentative list of 100 Common Words. This list was first started and compiled by Elaran, and working with Elaran, I refined it to this current list.

Rank ▲▼ English ▲▼ Sindarin ▲▼ Parts of Speech ▲▼ Note
1 the e(n) | i(n) Article Singular | Plural | (n) before vowels; e → soft mutation, i → nasal mutation.
2 be, exist as na- Verb Seen only in imperative form as no "be" & no i "be that / may"
3 to(words), at na Preposition Allative case
4 of na(n) Preposition Unnecessary word order is enough. Example: Dor Daedeloth
5 and a(h) Conjunction
6 a N/A Article
7 in mi Preposition
8 who/that | that i | sa | san Pronoun Relative | Dem. Nom./Subj. | Dem. Acc./Obj./Adj.
9 have | hold, have, *possess sav- | gar- Verb General Ownership/Experience | Physical Grasp/Control
10 I | me ni | nin Pronoun Nom./Subj. | Acc./Obj.
11 he/she/it | him/her/it te | ten Pronoun Nom./Subj. | Acc./Obj.
12 to, for an Preposition Dative case
13 no, not | no, not, negative û/law | ú-/ló- Adverb | Interj. | Prefix law¹ “sound” vs. law² “not”
14 (up)on bo Preposition “*on” [is, per editors, perhaps related to] √apa “touch”
15 (together) with gu | *ŷ Preposition ŷ for more than one other thing.
16 he (see #11) Pronoun
17 as, like | *as be, sui Preposition
18 you (thou | thee | you pl.) ci/cin | le/len | de/den Pronoun Nom./Subj. | Acc./Obj.
19 do, make car- Verb
20 at (see #3) Preposition
21 this se | sen Pronoun Dem. Nom./Subj. | Dem. Acc./Obj./Adj.
22 but ach Preposition
23 his/her(s)/its tín Possessive pronoun circumflex "î" vs. acute "í".
24 by (agent of) | beside, alongside mo | sa Preposition
25 from, of | away (from) o | o(d) Preposition o < ✶hō causing lenition. | o(d) < ✶aut causing stop mutation
26 *they | them ti | tin Pronoun Nom./Subj. | Acc./Obj.
27 we (excl.)/us (excl.) | we (incl.)/us (incl.) me/men | pe/pen Pronoun Nom./Subj. | Acc./Obj.
28 say, speak ped- Verb
29 her (see #23) Possessive pronoun
30 she (see #11) Pronoun
31 or egor Preposition
32 an N/A Article
33 will (future) | will, mean to, intend | *will atha- | nidh- | innas verb | verb | noun -atha(-) "will (future conjugation)"
34 my, *mine nín Possessive pronoun
35 one | one, alone | one, somebody, anybody min | er | pen Cardinal | Adjective | Pronoun
36 *all il Adjective
37 would (hypothetical) -ath(a)- & aen Verb, Adverb meant to be "...atha aen = would"
38 there | (in) there ennas | *tas Adverb not used like English "there is" [may interfere with "index finger"]
39 their(s) tín Possessive pronoun identical in form to #23, clarified by context
40 *what, who man Pronoun Interrogative | *Hypothetically like pronouns: ma(n)/van, e.g., "Ma agor han?"
41 so, then, (after) that *to Adverb
42 up(wards) am Adverb
43 out (of) ed Prepostion
44 if pi Adverb
45 *about o(h) Adverb os updated to o(h)
46 who (see both #8 & #40) Pronoun
47 get, catch, obtain, take | receive, *accept ged- [ng-] | cav- Verb
48 which (see #40) Pronoun
49 go men- Verb
50 me (see #10) Pronoun
51 when | when *maw/mo | io Interrogative | Conjunction
52 make (see #19) Verb
53 can, be (physically) able to pol- Verb
54 as, like | to like (see #17) | mav- Prepostion | Verb
55 time, occasion lû Noun
56 no (see #13) Interjection
57 just, *lonely air Adjective adjectives adverbially so "alone" works to say "alonely > on(e)ly / just"
58 him (see #11) Pronoun
59 know, have knowledge ista- Verb
60 seize | take mab- | nab- Verb *grasp, grab | lay hold of
61 people lî | gwaith | rim Verb (of one kind or origin) | [ᴱN.] men, folk | host, great number
62 into mî Preposition & Adverb
63 year | year | seasonal year în | idhrinn | lóran Noun year | *(lit.) year-circle | (lit.) growth-cycle
64 your (sg. fam. | *thy sg. polite | your pl.) cín | lín | dín Possesive Pronoun
65 good ma | maer Interjunction | Adjective excellent, that’s right | excellent, fair
66 some, few, several nodui Adjective
67 could (see both #37 & #53) Adverb debatable, possibly *"pelin mened = I can go" vs. "pelin aen mened = I could go"
68 them (see #26) Pronoun
69 see, perceive, look | see cen- | tíra- Verb
70 other egel Adjective
71 than, *beyond | across, athwart, over athar | thar Adjective alternative to "than" in English, e.g. "A is greater than B" → "A is great beyond B"
72 then (see #41) Adverb
73 now hí Adverb
74 look (towards), watch (over) tir- Verb
75 only | *only, alone (see #57) Adverb
76 come tol- Verb
77 its (see #23) Pronoun
78 over, above or | (see #71) Prepostion
79 think *sana- Verb
80 also eithro | aich Adverb
81 back ad- | dan [nd-] | galf Prefix | Adverb | Noun again, re- | back to, back on, back again | [of a body], shoulders [collectively]
82 after ab | cad Preposition | Adverb
83 employ, *use iuitha- Verb
84 two tâd Cardinal
85 how movan | naman Interrogative by means of what | with what
86 our(s) mín | pín Possesive Pronoun Exclusive | Inclusive
87 work ammuia- | muda- | tass Verb | Noun to work (hard) for, to earn | to labour, toil, *work | labour, task
88 first minui Ordinal
89 well; excellent, admirable mae | mael Adverb
90 road, way men (mên) Verb | Noun
91 even (see #80) Adjective
92 young, *new | fresh, new gwain | cîw Adjective
93 want aníra- | mer- Verb desire, *long for | hope, wish, desire, want
94 because (see #12) Preposition Can also be used as "because".
95 any *ae Pronoun
96 these si | sin Pronoun Dem. Nom./Subj. | Dem. Acc./Obj./Adj.
97 give anna- Verb
98 (whole) day, sunlight aur Noun
99 most, -est ro- Prefix (*superlative)
100 us (see #27) Pronoun