Table 7 Factor analysis results of the 5-point Likert scale items

18. Speaking: expressing thoughts and feelings (Imp.)

.81

.81

17. Speaking: interacting with ease (Imp.)

.81

.81

31. Speaking: expressing thoughts and feelings (SQ)

.80

.81

30. Speaking: interacting with ease (SQ)

.80

.80

19. Speaking: speaking in appropriate manners (Imp.)

.79

.79

32. Speaking: speaking in appropriate manners (SQ)

.79

.78

16. Speaking: exchanging factual information (Imp.)

.78

.78

29. Speaking: exchanging factual information (SQ)

.77

.75

37. Writing: summarizing texts (SQ)

.79

.80

38. Writing: reporting information and data (SQ)

.79

.80

23. Writing: writing clear and well-structured texts (Imp.)

.79

.79

36. Writing: writing clear and well-structured texts (SQ)

.79

.78

24. Writing: summarizing texts (Imp.)

.77

.76

25. Writing: reporting information and data (Imp.)

.77

.75

20. Reading: reading simple texts in publications (Imp.)

.78

.78

33. Reading: reading simple texts in publications (SQ)

.78

.77

35. Reading: reading simple factual texts (SQ)

.78

.77

22. Reading: reading simple factual texts (Imp.)

.77

.76

21. Reading: reading simplified literature (Imp.)

.77

.76

34. Reading: reading simplified literature (SQ)

.77

.76

15. Listening: understanding broadcasts and news (Imp.)

.78

.77

28. Listening: understanding broadcasts and news (SQ)

.78

.77

14. Listening: understanding discussions on general topics (Imp.)

.77

.75

27. Listening: understanding discussions on general topics (SQ)

.76

.74

13. Listening: understanding simple daily conversations (Imp.)

.72

.67

26. Listening: understanding simple daily conversations (SQ)

.70

.63

Eigenvalue

14.46

7.66

5.89

2.83

Variance explained (%)

40.38

17.92

15.62

7.42

Accumulated variance explained

40.38

58.30

73.92

82.00

Cronbach’s alpha

.95

.94

.92

.91