In Swedish, adjectives are inflected to express degree and agreement, and both types of inflection will be dealt with here. The lesson does not, however, treat adjectives that are inflected by means of mera and mest. The grammatical discussion will concern agreement inflection only, since this phenomenon is lacking in English and, as a consequence, may be somewhat difficult for an English-speaking learner to master. The word list together with the grammar discussion should contain sufficient information for you to be able to complete the exercises.
About Agreement Inflection in Swedish
An adjective always agrees in number and gender with the noun or pronoun it modifies. This is true whether it is part of a noun phrase or occurs on its own as subject or object complement. An adjective that acts as a modifier in a definite singular noun phrase will stand in its weak form. The pattern is somewhat different in the three comparison degrees, and I have therefore split the remainder of the discussion in three parts.
Adjectives in the positive have the richest inflectional morphology. They are inflected to express number (singular or plural), gender (common or neuter), and the distinction strong/weak. Many of the forms coincide, however, so that there is at most four distinct variants. There are two strong singular forms. One is used with nouns that are of the common gender: this is the basic form. The other is used with neuter nouns, and ends in -t. The neuter form is constructed differently depending on what the basic form is. If the basic form ends in a vowel, the neuter suffix will be -tt (e.g. blå, blått). If the basic form has an unstressed -en ending, the final -n will be replaced by -t (liten, litet). If the basic form ends in (VOWEL)+d, -d will be replaced by -tt (sned, snett). If the basic form ends in (CONSONANT)+d, -d will be replaced by -t (rund, runt). In all other cases, simply add a -t to the basic form (stor, stort; lång, långt; dålig, dåligt; etc.).
There is only one plural form of each adjective, so if an adjective modifies a plural noun or pronoun, it is not further inflected to express gender or the distinction strong/weak. The plural form is generally formed through the attachment of the suffix -a to the basic form.
There are at most two weak forms: one that is identical to the plural form (except in the case of liten, which has a distinct plural form, små) and can be used with any noun, and one ending in -e instead of -a, which can only be used to modify nouns that may represent male beings. Thus both den lilla pojken and den lille pojken are correct expressions, while there is no alternative form for the adjective in den lilla flickan. The use of the male weak form with plural nouns representing male beings is archaic and restricted to a few fixed expressions, such as de tre vise männen.
One exception to the rules above are adjectives ending in -a, such as bra, which are not inflected. Another exception are adjectives ending in -å, such as blå or grå, which need only be inflected to express the strong neuter form (blått, grått). Forms such as blåa and gråa do occur, however, at least in spoken language, but blå and grå would often be preferred both as weak and plural forms.
Adjectives in the comparative are not further inflected.
Adjectives in the superlative have at most three variant forms. They are not inflected for number or gender, but can express the strong/weak distinction. For superlatives ending in -ast, the weak form suffix is always -e, which means that they have no distinct male weak form (e.g. konstigast, konstigaste). Other adjectives will generally have both the -a form and the (male only) -e form (e.g. bäst, bästa, bäste). Compare the following phrase pairs:
den konstigaste pojken - den konstigaste flickan
den största/störste pojken - den största flickan
billig [comp: billigare] [sup: billigast] - cheap
blå [comp: blåare] [sup:blåast] - blue
bra [comp: bättre] [sup: bäst] - good
dum [comp: dummare] [sup: dummast] - stupid
dålig [comp: sämre] [sup: sämst] - bad
gammal [pos: plural = gamla] [comp: äldre] [sup: äldst] - old
konstig [comp: konstigare] [sup: konstigast] - strange/odd
liten [pos: weak = lilla/lille, plural = små] [comp: mindre] [superlative: minst] - little/small
lång [comp: längre] [sup: längst] - long/tall
röd [comp: rödare] [sup: rödast] - red
stor [comp: större] [sup: störst] - big/large