Notes on the Present Perfect video
We didn't cover much of the form in the video (focusing rather on usage), so here's what you should know:
we use 'have' or 'has' before the main verb: 'have' if the subject is plural, and 'has' if the subject is singular (the exception is that the pronouns I and you both use 'have')
many adverbs can come before 'have'/'has', between 'have'/'has' and the main verb, or after the main verb.
For questions, 'have'/'has' comes before the subject
For negative sentences, 'not' comes immediately after 'have'/'has'. This is often expressed through the contractions 'haven't' and 'hasn't'.
'Have' and 'has' often come as the back half of contractions ('ve and 's, respectively) with the nouns/pronouns that precede them.
We breezed though the common adverbs, so here's a closer look at some of them:
The difference between since and for is that since marks the time the action began, while for denotes the duration. You can change a for expression into a since expression by adding 'ago' at the end.
Already is the positive counterpart to yet (which is used in interrogative and negative usage); in other words, they mean the same thing, so which you use depends on whether the sentence is positive, negative, or interrogative.
Never is the negative counterpart to ever, which is used in questions. They don't have a positive counterpart.
With the unfinished usage, we often include time expressions involving the current moment, whether they are of short durations or long ones ('this afternoon', 'today', 'this month', 'this century', etc.)
Most ESOL resources go by British standards. Here are some ways that Americans typically use these adverbs differently:
Just is acceptable in Past Simple.
Already is acceptable in Past Simple.
Still is more commonly used as positive and with Present Simple. It's negative counterpart is anymore.
With experiences (answers to "have you ever...?"), we still use Present Perfect even if the subject has only done it once and doesn't plan on doing it again. We only change to Past Simple once we start talking more specifically about that instance.
We use Past Simple for more specifics than just when. It can be used to ask and answer questions like "how was it?", "who did you go with?", "why did you do it?". Another way to think about it is that you'd use Present Perfect at the introduction of this topic within a conversation, but any details that you go into after the introduction should probably be Past Simple.
The principles in this video are more-or-less the same for Past Perfect and Future Perfect; it's just a shift of perspective, or of timeline.
Notes on the Past Perfect video
The 'super-past' idea works not only for the Past Perfect Simple tense, but for the Past Perfect Continuous tense as well. We'll discuss the differences between the two in another video.
We talk about flashbacks, but those don't have to be an entire sequence of events; just a single verb counts (and is more likely in most scenarios).
Once you jump backward, if you don't return to your base time period immediately (eg. 3-4-1-1-2-4), you may or may not stick with past perfect until you return to the base time.
If staying in the super-past will last a while, you could probably use the past tenses instead of the past perfect tenses after the first verb of the super-past sequence.
The rules at this point are unclear. You can decide for yourself by balancing how much clarity the past perfect tenses may provide with how much easier it is to just use the past tenses.
On occasion, the first verb of a sentence or passage should be past perfect. Unfortunately, the way our numbering trick works, it's in the right place sequentially, so those are harder to catch. Instead, you need to pay attention to key time expressions that go along with that verb - expressions like 'already' and 'never'.
If two verbs in a sequence happen very close together and are linked with words lie 'before' and 'after' that very obviously tell us which happened first, you don't need to use Past Perfect (just Past will do).
Clauses that serve as time expressions are usually just in the Past Simple form (not the Past Perfect form, even if it happened earlier). Such clauses often begin with phrases like "by the time", "as soon as", "before", "when", "until", etc. (although the verb phrase that comes next could very well be Past Perfect). Compare these to instances in which we express the future with the Present Simple form.
For more on the form:
had is often shortened to the contracted 'd
negative verb phrases include not after had (or combined as hadn't)
interrogative sentences place the subject immediately after had (and before the main verb)
certain adverbs - such as already, never, and just - can be or should be placed between had and the main verb
Next in the Series
Present Perfect Continuous
The Present Perfect Continuous tense is, as its name suggests, is a merger between the Present Perfect tense and the Past Continuous tense, in terms of both form and usage. The better we understand the perfect and continuous aspects, the better we understand the Present Perfect Continuous Tense.
Perfect Tenses overview
All the perfect tenses (and perfect-continuous tenses) have a lot in common, whether they're past, present, or future. We'll look at what makes something perfect (or perfect-continuous) so that if you understand one perfect tense, you can understand them all.