These, for instance, could be used to help assess a student’s speaking level after a Skype discussion:
UNDERSTANDING A NATIVE SPEAKER INTERLOCUTOR
C2 Can understand any native speaker interlocutor, even on abstract and complex topics of a specialist nature beyond his/her own field, given an opportunity to adjust to a non-standard accent or dialect.
C1 Can understand in detail speech on abstract and complex topics of a specialist nature beyond his/her own field, though he/she may need to confirm occasional details, especially if the accent is unfamiliar.
B2 Can understand in detail what is said to him/her in the standard spoken language even in a noisy environment.
B1 Can follow clearly articulated speech directed at him/her in everyday conversation, though will sometimes have to ask for repetition of particular words and phrases.
A2 Can understand enough to manage simple, routine exchanges without undue effort.
Can generally understand clear, standard speech on familiar matters directed at him/her, provided he/she can ask for repetition or reformulation from time to time.
Can understand what is said clearly, slowly and directly to him/her in simple everyday conversation; can be made to understand, if the speaker can take the trouble.
A1
Can understand everyday expressions aimed at the satisfaction of simple needs of a concrete type, delivered directly to him/her in clear, slow and repeated speech by a sympathetic speaker.
Can understand questions and instructions addressed carefully and slowly to him/her and follow short, simple directions.
CONVERSATION
C2 Can converse comfortably and appropriately, unhampered by any linguistic limitations in conducting a full social and personal life.
C1 Can use language flexibly and effectively for social purposes, including emotional, allusive and joking usage.
B2 Can engage in extended conversation on most general topics in a clearly participatory fashion, even in a noisy environment.
Can sustain relationships with native speakers without unintentionally amusing or irritating them or requiring them to behave other than they would with a native speaker.
Can convey degrees of emotion and highlight the personal significance of events and experiences.
B1 Can enter unprepared into conversations on familiar topics.
Can follow clearly articulated speech directed at him/her in everyday conversation, though will sometimes have to ask for repetition of particular words and phrases.
Can maintain a conversation or discussion but may sometimes be difficult to follow when trying to say exactly what he/she would like to.
Can express and respond to feelings such as surprise, happiness, sadness, interest and indifference.
A2 Can establish social contact: greetings and farewells; introductions; giving thanks.
Can generally understand clear, standard speech on familiar matters directed at him/her, provided he/she can ask for repetition or reformulation from time to time.
Can participate in short conversations in routine contexts on topics of interest.
Can express how he/she feels in simple terms, and express thanks.
Can handle very short social exchanges but is rarely able to understand enough to keep conversation going of his/her own accord, though he/she can be made to understand if the speaker will take the trouble.
Can use simple everyday polite forms of greeting and address
Can make and respond to invitations, invitations and apologies.
Can say what he/she likes and dislikes.
A1 Can make an introduction and use basic greeting and leave-taking expressions.
Can ask how people are and react to news.
Can understand everyday expressions aimed at the satisfaction of simple needs of a concrete type, delivered directly to him/her in clear, slow and repeated speech by a sympathetic speaker.
INFORMAL DISCUSSION (WITH FRIENDS)
C2 No descriptor available
C1 Can easily follow and contribute to complex interactions between third parties in group discussion even on abstract, complex unfamiliar topics.
B2 Can keep up with an animated discussion between native speakers
Can express his/her ideas and opinions with precision, present and respond to complex lines of argument convincingly.
Can take an active part in informal discussion in familiar contexts, commenting, putting point of view clearly, evaluating alternative proposals and making and responding to hypotheses.
Can with some effort catch much of what is said around him/her in discussion, but may find it difficult to participate effectively in discussion with several native speakers who do not modify their language in any way.
Can account for and sustain his/her opinions in discussion by providing relevant explanations, arguments and comments.
B1 Can follow much of what is said around him/her on general topics provided interlocutors avoid very idiomatic usage and articulate clearly.
Can express his/her thoughts about abstract or cultural topics such as music, films. Can explain why something is a problem.
Can give brief comments on the views of others.
Can compare and contrast alternatives, discussing what to do, where to go, who or which to choose etc.
Can generally follow the main points in an informal discussion with friends provided speech is clearly articulated in standard dialect.
Can give or seek personal views and opinions in discussing topics of interest.
Can make his/her opinions and reactions understood as regards solutions to problems or practical questions of where to go, what to do, how to organise an event (e.g. an outing).
Can express belief, opinion, agreement and disagreement politely.
A2 Can generally identify the topic of discussion around her which is conducted slowly and clearly.
Can discuss what to do in the evening, at the weekend.
Can make and respond to suggestions.
Can agree and disagree with others.
Can discuss everyday practical issues in a simple way when addressed clearly, slowly and directly.
Can discuss what to do, where to go and make arrangements to meet.
A1 No descriptors available
from the Common European Framework of Reference for Languages:
Learning, teaching, assessment: Structured overview of all CEFR scales