present participle.noun
Grammar – a participle expressing present action, formed in English by the infinitive plus -ing and used to express present action in relation to the time indicated by the finite verb in its clause, to form progressive tenses with the auxiliary be, and to function as a verbal adjective

intensive.adjective
Grammar – tending to emphasize or intensify (an intensive adverb)
intensive.noun
Grammar – a linguistic element, such as the adverb extremely or awfully, that provides force or emphasis; also called intensifier

singular.adjective
Grammar –  of, relating to, or being a noun, pronoun, or adjective denoting a single person or thing or several entities considered as a single unit

preterit or preterite.adjective
Grammar – of, relating to, or being the verb tense that describes a past action or state
preterit.noun
the verb form expressing or describing a past action or condition; a verb in the preterit form

prefix, prefixed, prefixing, prefixes.transitive verbs
to put or attach before or in front of
Grammar – to add as a prefix; to add a prefix to
prefix.noun-an affix, such as dis- in disbelieve, put before a word to produce a derivative word or an inflected form

suffix.noun
Grammar – an affix added to the end of a word or stem, serving to form a new word or functioning as an inflectional ending, such as -ness in gentleness, -ing in walking, or -s in sits
suffix, suffixed, suffixing, suffixes.transitive verbs
to add as a suffix. 
suffixal.adjective
suffixion.noun

base.noun
Linguistics – a morpheme or morphemes regarded as a form to which affixes or other bases may be added

stem.noun
Linguistics – the main part of a word to which affixes are added

root.noun
Linguistics – the element that carries the main component of meaning in a word and provides the basis from which a word is derived by adding affixes or inflectional endings or by phonetic-change; such an element reconstructed for a protolanguage-(a language that is the recorded or hypothetical ancestor of another language or group of languages); also called radical

conditional.adjective
a mood, tense, clause, or word expressing a condition

condition.noun
the dependent clause of a conditional sentence