clever的比较级是cleverer还是more clever?

more clever 和 cleverer 都可以

英语的形容词和副词的比较级和最高级的构成
一 规则变化
1 单音节以及少数双音节的词,后面直接加 -er , -est
2以-e结尾的，在后面加-r , -st
3以辅音字母＋y结尾的词，把y变成i,再加-er , -est
[注〕
shy ---- shyer , shyest / shier , shiest
4重读闭音节的词，要双写词尾字母，再加-er , -est
5多音节的词，要在前面加 more-, most-
〔注〕
少数单音节词前面加 more-, most- 构成比较级和最高级
tired ---- more tired , most tired
fond ----- more fond , most fond
glad ----- more glad , most glad
bored ---- more bored , most bored
pleased---- more pleased , most pleased

二不规则变化
good /well------- better ,best
bad/badly/ill------ worse , worst
many/much-------more , most
little ------ less , least
far ---- farther, farthes / firther , furthest
old ---- older , oldest (GA)
---- older , oldest / elder , eldest (GB)

三下列形容词和副词的比较级和最高级有两种形式
cruel----- crueler, cruelest /
more cruel , most cruel
strict---- stricter , strictest /
more strict , most strict
often----- oftener , oftenest /
more often , most often
friendly------ friendlier , friendliest /
more friendly , most friendly
clever----- cleverer, cleverest /
more clever , most clever

四 下列形容词和副词没有比较级和最高（即表示”最高程度”或”绝对状态”的形容词和副词没有比较级和最高级）
empty , wrong , perfect , unique , extreme , excellent , favourite (GB)/ favorite (GA) , true , right , correct , extremely ...

more clever 或 cleverer 。

两个都可以。

cleverer