Future Tense
Future Tense is used in Greek to describe a future action that can be either simple or continuous. When using Future Tense, the speaker is usually fully convinced that this action will happen. Greek Future Tense can be mostly translated by either English Future Simple or Future Continuous (i.e. λύσω can be translated as I will untie, or I will be untying). Future Tense is sometimes used as a command, that can be rendered in English with will or shall (You will open the door! or You shall open the door!).
Future Active Indicative verbs are using the Second Principal Part as the foundation. The Second Principal Part is formed by adding the -σ- suffix to the stem of the First Principal Part, and then the -ω ending. I.e. λυ- + -σ- + -ω => λύσω. However, additional contractions and changes often happen. Here are some of the categories of quasi-regular verbs:
Contract Verbs (stem ends in ε, ο, or α). Often the last vowel changes. Epsilon(ε) turns into Eta(η), Omicron(ο) into Omega(ω), and Alpha(α) into Eta(η). For example, the Second Principal Part of ποιέω is ποιήσω. And the Second Principal Part of σταυρόω is σταυρώσω.
Consonant contractions. Often, some of the consonants contract together with -σ- suffix into other consonants. Labial consonants π, β, φ can turn into ψ. Palatal consonants κ, γ, χ can turn into ξ. And dental consonants τ, δ, θ, ζ can turn into σ. For example, the Second Principal Part of πέμπω is πέμψω. And the Second Principal Part of ἔχω is ἕξω.
Liquid Verbs (stem ends in λ, ν, ρ, or μ). These verbs go through a strange process. Let's take κρίνω as an example. First, together with the suffix an ε is added, so that we have κρινέσω. Then, however, the sigma itself is dropped, and we end up with κρινέω, which is further contracted (see vowel contractions for details) so that in the end we have κρινῶ as the Second Principal Part. Sometimes also, the doubled liquid consonant is reduced to a single one. For example, the Second Principal Part of στέλλω is στελῶ.
There are also fully irregular verbs. For such verbs, it is impossible to deduce the Second Principal Part out of the first. For example, the Second Principal Part of λέγω is ἐρῶ.
Future Active Indicative uses the same endings as Present Active Indicative. Below is the table that shows the conjugation of λύω:
Reminder: The ν in brackets is a movable ν. It often appears before words starting with vowels or at the end of a sentence or a clause. But it can be omitted as well.
The forms of Future Indicative Middle are given in the following table (you can read more about the use of Middle and Passive voices here):
The Future Infinitive Active form is given by λύσειν, and can be roughly translated by to be about to untie.
The Future Infinitive Middle form is given by λύσεσθαι, and can be roughly translated by to be about to untie myself.
The Passive voice of the Future Tense uses the sixth Principal Part as its basis (see here about the formation of the sixth Principal Part). One needs to take the sixth Principal Part, take away the epsilon augment, and then add -ησ- at the end of the stem. After that, one can add the same set of endings as for Future Middle and Present Middle\Passive. This procedure almost always occurs regularly. The forms of the Future Indicative Passive are given below:
