What is the meaning of -t?

Forms the past tense and/or past participle of some verbs (leapt, kept, dreamt, blest, etc.)

An excrescent ending appended to words suffixed with -s.

Used to form nouns from verbs of action; equivalent to -th.

Verbs formed from nouns or adjectives (compare English -ate, -ize), frequently having a causative force, or modified from an existing verb into a frequentative verb

An intensifier added to the end of words ending in <d>, representing a change in pronunciation from /d/ to /t/. (Should we delete this sense?)

Marks the instrumental case: using; by means of

Marks the malefactive case: for ...'s nuisance

Marks the inessive case: in

Marks the temporal case: in; within

Marks the stative case: while being (in the state of)

Adverb suffix. -ly, -y

Nominative/definite/plural suffix.

Accusative/definite/plural suffix.

Genitive/definite/singular suffix.

Genitive/definite/plural suffix.

Dative/definite/singular suffix.

Dative/definite/plural suffix.

Ablative/definite/singular suffix.

Ablative/definite/plural suffix.

Causative suffix.

Participle-forming dependent verb suffix.

Used to form feminine singular forms of nouns.

Used to form feminine singular forms of adjectives.

An unpronounced graphical suffix occasionally added to adjectives without regard for gender.

Converts nouns and prepositions into feminine adjectives: the feminine nisba adjective ending.

Forms adverbs from certain adjectives; -ly

Forms the infinitive of anomalous verbs, weak verbs (except for fourth weak verbs with a geminated stem), and causative biliteral verbs.

Forms the pronominal state of the infinitive of transitive third-weak verbs, and occasionally also biliteral and triliteral verbs, used when a suffix pronoun is attached to the infinitive.

Forms the complementary infinitive of all verbs.

Forms the subjunctive of the irregular verb jnj and the anomalous verb jwj.

Forms the terminative of all verbs.

Alternative form of et

Alternative form of te

Used to form the nominative/accusative plural; -s

plural suffix in the absolutive case. Numbers vary between singular -q and plural -t depending on whether they modify a noun or are being used for counting

Diminutive suffix

Alternative form of -th (abstract nominal suffix)

Alternative form of -the (abstract nominal suffix)

Alternative form of -the (ordinal suffix)

Used to form adverbs from adjectives

Used to make neuter forms of adjectives

Used to make past participle of some weakly inflected verbs

Alternative form of -a, used in between vowels

Alternative form of -t, used following hard consonants

Used to form adverbs from adjectives

Used to make neuter forms of adjectives

Plural verb suffix.

Nominal absolutive suffix.

Used to form adverbs from adjectives; -ly.

Used to make neuter forms of adjectives.

Used to form past participles of some verbs, like -et does.

forms the second and third person singular of the present tense

forms the gij - form in both present and past tense

forms the plural form of the imperative

forms the past participle of weak verbs the root of which ends in a voiceless consonant

forms certain verbal nouns, mostly of strong verbs

Forms the nominative and accusative plural.

Forms the accusative forms of the personal pronouns and the interrogative pronoun ken.

Forms the second person singular of verbs.

Verb suffix for the third-person singular of the present tense.

Verb suffix for the second-person plural of the present and past tenses.

Verb suffix for the past participle of weak verbs, together with the prefix ge- if the first syllable of the verb stem is stressed. See ge- -t for more.

Forms the accusative case for nouns, adjectives, pronouns and numerals.

past-tense and past-participle suffix (homonymous form in the vast majority of verbs):

1. -ed, -t (forms the past tense of a verb)

   -ed, -t (forms the past tense of a verb)

   -ed, -t (forms the past participle of a verb)

   Added to a verb to form a noun.

   in (added to a noun or an adjective to form the locative case)

   A causative (e.g. kelt, teremt) or instantaneous (e.g. ért, tilt) suffix for verbs.

   forms nouns from adjectives: -th, -ness

   used to form the second-person plural present and imperative of all verbs (except those with a stem in -d or -t, see usage note)

   used to form the third-person singular present of all regular and some irregular verbs

   used to form the past participle of all regular and some irregular verbs (often with the prefix ge-, see there)

   used to form the first-person singular, third-person singular, and second-person plural past tense and past subjunctive of some irregular verbs

   Alternative form of -it

   Forms adverbs of manner from adjectives.

   Forms adverbs of time.

   Forms the comparative of adjectives.

   Forms ordinal numbers from cardinals.

   The ending of the nominative plural.

   The ending of the infinitive.

   Suffix to create the definite singular form of neuter nouns ending in an unstressed vowel: hjärta (“heart”) → hjärtat (“the heart”)

   Suffix for creating adverbs out of adjectives: långsam (“slow”) → långsamt (“slowly”)

   Suffix used on the positive form of adjectives to denote that the corresponding noun is of neuter gender, indefinite form: en gul bil (“a yellow car”) → ett gult hus (“a yellow house”), the latter being neuter. However, the -a suffix is used for definite form independent of gender: den gula bilen (“the yellow car”) → det gula huset (“the yellow house”).

   Suffix to form the past participle of weakly inflected verbs, to be used when the corresponding participle belongs with a neuter noun in indefinite singular form.

   Suffix for forming supine of verbs of the first (ar-verbs) and second (weak er-verbs) conjugations; see also -it and -tt

   Forms causative verbs usually from polysyllabic stems ending in a vowel or 'l' or 'r'.

   Source: wiktionary.org