STUDENT EXAMPLE:
The professor tries to explain the abstract concept of freedom.
PELIC Arabic male level 5 writing class
The plural form is more common in iWeb corpus:
1 ABSTRACT CONCEPTS 2856
2 ABSTRACT CONCEPT 1883
further collocates in iWeb:
1 CONCEPTS 2978
2 AN 1170
3 SUCH 302
4 UNDERSTAND 183
5 CONCRETE 149
6 RATHER 102
7 UNDERSTANDING 101
8 ABILITY 74
9 GRASP 69
10 COMPLEX 51
11 DIFFICULT 45
12 REPRESENT 43
13 IDEAS 43
14 COMMUNICATE 40
15 OBJECTS 40
16 LANGUAGE 40
17 VISUAL 37
18 EXPLAIN 34
19 MATHEMATICS 32
20 TANGIBLE 30
concepts B2 an A1 such A2 understand A1 concrete B2 rather B1 understanding A1 ability B1 grasp C1 complex B2 difficult A1 represent B2 ideas A2 communicate B1 objects B1 language A1 visual B2 explain A2 mathematics tangible C2