Adjective spelling changes (-m, -n)

Adjectives usually add -t for ett words (neuter) and -a for plurals. But adjectives ending in -m or -n after a short vowel have special spelling rules to keep their pronunciation consistent.

Dropping the "n" for neuter words

When an adjective ends in a double -n (like noggrann, meticulous), it drops one "n" before adding the neuter -t ending to avoid a cluster of three consonants. The plural form adds -a, keeping the double "n".

The tailor is very meticulous.
Skräddaren är mycket noggrann.
He sews a careful stitch in the fabric.
Han syr ett noggrant stygn i tyget.
The hem is sewn with small, careful stitches.
Fållen sys med små, noggranna stygn.

The same rule applies to words like tunn (thin), which becomes tunt (ett words) and tunna (plural):

He uses thin paper.
Han använder tunt papper.
The needles are very thin.
Nålarna är väldigt tunna.

Doubling the "m" for plurals

For adjectives ending in a short vowel followed by a single -m, you double the "m" when adding the plural -a. This double consonant keeps the preceding vowel sound short. Watch how öm (sore) becomes ömma:

The seamstress's finger is sore today.
Sömmerskan är öm i fingret idag.
Her hands are very sore.
Hennes händer är väldigt ömma.

This doubling rule also applies to all adjectives ending in the suffix -sam, like följsam (supple) or varsam (careful). Their neuter forms just take a normal -t without doubling (följsamt, varsamt), but the plurals double the "m" (följsamma, varsamma).

The linen is a very supple material.
Linnet är ett mycket följsamt material.
The seamstress chooses supple fabrics for the dress.
Sömmerskan väljer följsamma tyger till klänningen.