Now, let's talk about past tenses in German language. When we describe things that happened in the past, we can use 2 different tenses - Präteritum (simple past tense) and Perfekt (present perfect tense).

Basically, for the modal verbs or verbs haben/sein we use Präteritum whenever we speak about something that happened in the past (it wouldn't sound very understandable or make sense to use Perfekt, they are just mostly used in Präteritum). For all the other verbs, it's most common to use Perfekt, but we can use also Präteritum. Präteritum would be used if we wanted to speak like we were for example in an old movie, or are reading from some very old book.

Now that we have differentiated when to use one and when other, we want to see how they are built.

Präteritum

In some of the previous topics, we had lists of how Präteritum looks like for modal verbs and also for verbs sein/haben. Now, we will show how to build Präteritum for all the other verbs.

For weak verbs, we have the same basis as for the present (we remove -en). Then we add -te and add suffixes /, -st /, -n, -t, -n. (they are very much like the ones for present, we just have e already, so we don't add it again; it would be weird to have for example lern+te+e for ich).

For strong verbs, the basis is different, you mostly find it from the table and then later memorize it, there isn't any special rule that we could use, but you will remember the most important ones very fast because they are often repeated and between some of them there are some similarities. When you get the basis, you add suffixes /, -(e)st, /,-en, -t, -en.

For 2nd person singular (du), we see that there are two options -est / -st (that's why e is in bracket). We use -st when basis already ends with letter e, so they don't double themselves and we use -est when the basis ends with any other letter.

For mixed verbs, this is the best place to see how they got their name. They have irregular basis, just like strong verbs, but they also add -te and suffixes just like weak verbs. It will be easier to see what I am talking about on some examples:

lernen weak verb

Singular Plural

1. ich lernte 1. wir lernten

2. du lerntest 2. ihr lerntet

3. er/sie/es lernte 3. sie/Sie lernten

lesen strong verb

Singular Plural

1. ich las 1. wir lasen

2. du lasest 2. ihr last

3. er/sie/es las 3. sie/Sie lasen

denken mixed verb

Singular Plural

1. ich dachte 1. wir dachten

2. du dachtest 2. ihr dachtet

3. er/sie/es dachte 3. sie/Sie dachten

Perfekt

Perfekt is not a simple tense, so it consists from two parts: auxiliary verb + participle.

When we talked about verbs haben and sein in some previous topic, we mentioned that they are used in this case. So, for the auxiliary verb we use present of verb haben/sein. The question is how we decide which one to use?

There are a couple of rules that help us with that.

We use haben when:

1. verbs can have an accusative object next to them (kaufen - buy; buy something)
2. verbs cannot have an accusative object and they also don't express any change of state/place (aufräumen - to clean room/space)
3. we have reflexive verbs (verbs with sich)

We use sein when:

1. verbs cannot have an accusative object or represent change of state/place (gehen, fallen)

Next, we have participle. We have general rules of how we get it, but there are a lot of exceptions to these rules, so sometimes you will know what is exception and use it right away, or for some strong verbs, you will have to look into table and find what participle for that verb is. With time passing, you will learn them and not have to look it up anymore.

General rules:

For weak and mixed verbs:

- we find the basis by removing -en from the end of the verb

- we add ge- in the beginning and -t in the end

lernen-----> lern -------> gelernt

For strong verbs:

- we just add ge- in the beginning

sehen -----> gesehen

Some rules about exceptions:

- if basis we get ends with letters d or t, we add -et instead of just -t for easier pronunciation

warten ----> wart -----> gewartet

- if verbs end in -ieren, they don't have ge- in the beginning of participle

studieren -----> studiert

We already mentioned next two rules when we talked about inseparable and separable prefixes in some previous topic, but I will repeat them here because they are important:

- if verb is formed by adding inseparable prefix to some verb, we just don't have ge- in the beginning of the participle

verstehen -----> verstanden

- if verb is formed by adding separable prefix to some verb, the structure of participle is prefix + ge + participle of the original verb

aufstehen -----> aufgestanden

Let's just for the end see two examples of Perfekt:

Ich habe das Buch gekauft. -----> I bought the book.

Ich bin ins Laden gegangen. -----> I went to the store.

Important thing to note: Auxiliary verb takes position 2 in sentence (as verb usually does) and participle always goes to the last position!