Grammatical Tenses

Aspect is a grammatical use of verbs, related to but separate from "tense."

Tense places an event on a time continuum in relation to the time of utterance, whereas the continuum of time for aspectis limited to the construction (the sentence) in question. In this regard, aspect deals with the "view" of an action, how it relates to the present.

This is illustrated in English using separate tenses, helper verbs, and adverbs. The most obvious are the perfect and progressive, aka continuous, tenses.

Compare the sentences:

I eat (present, but indicates habitual rather than present)

I am eating (present progressive)

I have eaten (present perfect) - actually indicates a completed past action

I have been eating (present perfect progressive) - past continuous action

I am about to eat (a form of future action)

I am going to eat (a form of future action)

I eat every day (habitual action)

Various languages may use separate verb forms, or prefixes, or suffixes, to indicate the aspect of an action. In English, the two major categories of aspect are Perfective (activity takes place)and Progressive (also continuous, an activity is still taking place). In certain languages, such as Russian, Hindi, a third category, Imperfective, also exists.

* see the related link to English aspects and their uses

* see the related question for sentences using the word "aspect"

Teach form and function.eg

form of present perfect is - have/has + past participle.

function of present perfect is to talk about something that happened in the past but is significant now in the present. (and other functions).

Then find some communicative activity where the students can practice the function.

eg Meeting someone:

A: Where to you come from?

B: I come from Switzerland.

A: Oh, really! I have been to Switzerland.

The present progressive is formed with am, is, or are + a present participle (which always ends in -ing).

I am judging (first person singular)

We are judging (first person plural)

You are judging (second person singular and plural)

He/she/it is judging (third person singular)

They are judging (third person plural)

You can use either term. 'Burned' and 'burnt' are variations on the same word, just like 'learned' and 'learnt'.

So you could say, 'They were worried the cake had burned', or 'They were worried the cake had burnt'.