Diminutives are frequently used either to specify an objective nuance or for subjective reasons: familiarity, tenderness, contempt.
A/ Wet consonants: diminutives can be formed by wetting dental consonants and sometimes strong guttural consonants. Examples: eder, beautiful; eyer, cute; Madalen, Magdalena; Mayalen, Magdalenita; tipi, little; ttipi, little one; aita, father; atta, little father; polit, pretty; pollit, cute; oilo, chicken; pollito; ario, light; ariñ, light; onon, bonbon; oñoñ, bonbon; sagu, mouse; xagu, little mouse; isuri, to turn; ixuri, to overturn; zakhur, dog; txakur, little dog; tzar, wicked; txar, bad; bero, hot; bero, warm. Sometimes diminutives give rise to repetitions: E.g.: egizu hosi xuxen eta zuzen, do it quickly and well. Other times the diminutive replaces the normal voice: e.g.: jastatu for dastatu; ixuri, for isuri, etc.
B/ Diminutive suffixes. a) -ño, -tto, -xo. E.g.: lore, flower; loretto or loreño, little flower; haur, child; haurño, haurxo, little boy; emeki, sweetly; emekiño, sweetly (but in diminutive). b) -sko, -xko, a little, quite a bit, quite a lot, passably. E.g.: urrun, far; urrunsko, quite far; guti, a little; gutixko, a little; hara, that way; haraxko, a little that way; gora, high; goraxko, a little high; ongi, well; ongixko, a little well; ontu, mature; ontuxko, mature. c) The suffix -xe, softens a good number of words whose translation into Spanish is not always possible; after n and r it generally becomes -txe; it affects: 1.° the interrogatives non, where? noiz, when? and nola, how? E.g.: nuntxe da, where can it be? 2 ° Demonstrative pronouns: e.g.: hauxe, this very one: horixe, that very one. 3 ° The demonstrative adverbs of place, manner, presentation and their derivatives: e.g.: hortze, ahi; holaxe, asi mismo; bezalaxe, un poco como. 4 ° Adverbs: orain, now; orduan, then; aintzinean, yesteryear; and ondoan, after. E.g.: oraintxe, right now; ondoxean, a little later; orduxean, around that time. 5º Past participles: e.g.: egintxe, almost done; hasixe, a little started; ontuxe, almost ripe. 6º Comparatives in -ago, superlatives in -en and excessives in -egi. E.g.: geroxeago, a little later. Remarks: I. In declined forms, -xe is placed before the casual suffix. E.g.: orduxean, towards this moment; aintzintxean, a little before; egintxea, almost done; hauek, these very ones. However, in the inessive we find orduantxe, towards this moment, hortantxe, in that. II. xe always precedes the comparative, excessive and superlative suffixes, and nowadays the e of -xe disappears before the initial vowel of these suffixes. E.g.: handixago, a little bit bigger; handixegi, a little bit too big; handixena, the biggest. III. Instead of -xe, some say -xet or -xek (rare) before adverbs. E.g.: hortxet, right there; holaxet, like that; hortxek, right there; holaxek, right there. d) The suffix -tsu, almost, a little, can affect: 1.° interrogative pronouns and adverbs. E.g.: nortsu da, who is more or less; nuntsu, where a little more or less; zonbatsu, how much a little more or less? 2. demonstrative adverbs of place, manner, quantity and their derivatives. E.g.: nolatsu, how, a little more or less; halatsu, so, a little more or less; hantsu, about there; hura bezalatsuko, almost like him; hanbatsuko, about a little. 3° Words indicating order or measure: e.g.: azkentsu, towards the last, almost the last; erditsuak hor ziren, about half was there; artetsuan, towards the middle. e) -ska, -xka, -xkila, -skila, are added to nouns and adjectives. E.g.: jaun, sir; jaunskila, master; hazkarxka, quite strong.
C/ Derogatory compound. Basque also uses derogatory compound words: the word is ed but using an m or a b when it is ed. E.g.: elhemelheak dira, they're a bunch of words; handi-mandiak, potentates; nahas-mahas, jumble; salsamaltsa, unappetising sauce; sino-mino, mannerisms; tira-bira, little strips; duda-muda, doubts; hautsi-mautsi, compromises.... Ref. Lafitte, Pierre: Grammaire basque, published in the city of Bayonne in 1962.